Characters / Hey Arnold! - Arnold Shortman

Hey Arnold! character index
Arnold Shortman | Helga G. Pataki | Students of P.S. 118: Mr. Simmons' Class, Other Students | The Adults: Part One, Part Two | Other Kids

---

WARNING: There are plenty of unmarked spoilers throughout (spoilers from Hey Arnold! The Jungle Movie WILL be marked as necessary), so read at your own risk.

Arnold Phillip Shortman

"Whatever you say, Helga."

^{Arnold as he appears in The Jungle Movie}

Voiced by:
J.D. Daniels (pilot episode)
Toran Caudell (season 1 and singing voice in "What's Opera, Arnold?")
Phillip Van Dyke (seasons 2 and 3)
Spencer Klein (season 4, most of season 5 and The Movie)
Alex D. Linz ("April Fool's Day" and "The Journal")
Mason Vale Cotton (The Jungle Movie)
Rusty Flood (preschool/toddler Arnold in "Helga on the Couch" and "Parents Day")

"You think you're so bad, but deep down, I don't think you are. In fact, I have a feeling that you're probably a nice, normal person. And maybe one day, you won't be so afraid to show it."

The main protagonist of Hey Arnold!. Ambitious yet chilled, he always strives to do the right thing and wants everyone to get along.

---

A-L

• The Ace: He can do anything. By the time of the first movie, most of the neighborhood believes he can save them from having to sell up and move. And he does.
• Adorably Precocious Child: Arnold is one of the most mature animated pre-teens ever imagined. Even adults have come to him for guidance at times. Given he's been without parents for most of his childhood and the adults in his immediate vicinity are a bit odd, he had to partially raise himself.
• Affectionate Nickname:
  • "Short man" from his grandfather (which is a pun on his surname "Shortman").
  • "Arnie" from Coach Wittenberg.
  • While she normally uses it in an insulting manner, Helga occasionally calls him "Football Head" affectionately, implying it to be an Insult of Endearment.
  • Grandma Pookie has the habit of calling Arnold "Kimba" (he somewhat resembles a lion).
• All-Loving Hero: He never opts for violence (aside from "Mugged"), and would rather have everyone get along. He's even nice to Helga more often than not, despite her frequent bullying.
• Always Someone Better: So much that even Rhonda can't compare herself to him.
• Anime Hair: It's spiky, and lampshaded a lot throughout the series. In fact, it's so iconic, that's it's weird to see him have it combed or hidden beneath a hat ("Helga Masquerade", "Married").
• Apologises a Lot: When he's caused an accident, he'll constantly say he's sorry to show his remorse. Happens in "Eugene's Bike" when Arnold inadvertently causes a lot of problems for Eugene, from his biking accident to accidentally flipping a switch on the hospital bed causing Eugene to get hurt.
• Arrogant Kung-Fu Guy: After learning karate in "Mugged", Arnold's newfound power ends up going to his head and he acts aggressively towards everyone. After he goes too far and assaults a man who was only trying to ask for help to find the bus stop, he quickly snaps out of it, even showing restraint against the guy that spurred him into taking self-defense lessons.
• Art Evolution: He started out wearing an orange sweater in the pilot and his head was shaped more like a blimp before changing into a taco-shaped look. His sweater also switched from orange (in the pilot) to turquoise (Season 1), and then to teal (Season 2 onwards).
• Author Avatar: In this chatroom, Word of God states that he relates to Arnold the most.
• Badass Pacifist: Arnold almost never resorts to violence to solve his problems, and was able to fake being Ax-Crazy well enough to stop Harold from fighting him.
• Bare-Fisted Monk: He was taught Karate by his grandma, and he took to it like a fish to water.
• Belligerent Sexual Tension: With Helga — Although he is definitely not a jerk, Helga's constant bullying has made him occasionally hostile towards her (or at least as much as he can be) and Helga is one of the greatest Tsunderes you will ever see.
• Berserk Button:
  • Arnold really didn't like being called a jinx in "Eugene's Birthday".
  • Making fun of his pet pig, Abner, won't fly with him. He was almost violent when it happened in "The Pig War."
  • Calling him an "orphan" will hit some serious notes with him, as it reminds him of his long-lost parents and sends him into a Heroic BSoD.
• Betty and Veronica: The "Archie" for Helga's "Veronica" (rude, violent, Loving Bully) and Lila's "Betty" (optimistic, proper, All-Loving Hero). In the end, Lila doesn't reciprocate Arnold's feelings for her and Word of God confirms that he would return Helga's feelings, with the two marrying each other as adults.
• Beware the Nice Ones: Arnold is usually reserved and really friendly, but he's not afraid to exhibit his savagery should he be messed with. When the Sewer King repeatedly weaseled out of handing back Grandpa Phil's watch despite their agreement, Arnold tackled him for it.
• Big Damn Kiss: With Helga in The Jungle Movie after he's not only come to finally accept her Love Confession, but realizing her true Hidden Depths and the person she truly is.
• Birds of a Feather: It might not seem like it at first, but he and Helga actually have a lot in common. Both are artistic and imaginative, mature for their age (for better [Troubling Unchildlike Behavior or worse]]), and both deal with the heartbreak centered around pining for unrequited love.
• Blue Is Heroic: His outfit is mainly blue and he's the titular All-Loving Hero protagonist. He also mentions that blue is his favorite color in the episode "Married."
• Born During a Storm: Arnold's mother went into labor during a volcanic eruption in the middle of the jungle. The eruption stopped the exact second after Arnold was born.
• Break the Cutie: Losing his cap puts Arnold in a funk, as it was a gift from his long-lost parents and one of his earliest memories.
• Broken Hero: Arnold is a well-adjusted kid and not exactly depressed, but he is somewhat brooding and pretty blue most of the time. He doesn't talk about it often, but a few instances make it clear that the absence of his parents and his lack of knowledge of their fate weighs pretty heavily on him which drives him to overcompensate by being a do-gooder. Then of course by the time of The Jungle Movie he has the extra burden of actually being The Chosen One.
• Brooding Boy, Gentle Girl: Gender Inverted and Zigzagged with Helga. Arnold is an All-Loving Hero who gives emotional advice and support to others (including Helga) when they are in some personal crisis; Helga is a Broken Bird who acts as a bully to hide her insecurities and vulnerable side. However, because the latter acts as if she hates the former, they hardly make any development in their relationship resulting in more friction. Until The Jungle Movie comes along anyway.
• Characterization Marches On: He was more eccentric and naïve early on, and even had moments of being incredibly weak-willed and hot-headed. His virtuous side was there originally, but in a more spacey, matter-of-fact way. He was also a chronic daydreamer; many episodes in season 1 begin with a dream sequence. These were dropped for season 2, and most of his vices were phased out as he became the Only Sane Man and Wise Beyond His Years (although he remained Oblivious to Love throughout). Towards the very end of the series he abruptly developed a bit of a mischievous streak.
• Cheerful Child: Although, it's more in the sense of being optimistic and good-natured than hyperactive and playful.
• Chick Magnet: Arnold has had three girls like him over the series. Helga, Lila (at first), and Timberly. His sixth-grade date liked him enough to kiss him at the end of the night (despite knowing he's a fourth grader), Patty even called him cute once and Rhonda seemed interested with the idea of kissing him in Romeo and Juliet. In fact, Sheena, Nadine and Phoebe seem happy with the idea of it too, with Sheena being the one to tell the others he'll be Romeo, quite excitedly too.
• Childhood Friend Romance: With Helga — They first met in pre-school, have a complicated relationship by elementary school (mostly due to Helga being unable to express her proper feelings to him), and Word of God confirms that the two end up Happily Married as adults.
• The Chosen One: He's the fabled "Child of the Volcano" revered by the Green-Eyed People. In fact, this partly justifies his football-shaped head (not only did he inherit it from his mom, the God of the Green-Eyed People has such a head) He was also prophesied to use the Corazon to cure the Hidden City of the sleeping sickness. Subverted to some degree as it's actually Helga who fulfills the prophecy and cures the sleeping sickness with her locket.
• Cloudcuckoolander: At the beginning of the series he would frequently delve into euphoric daydreams. This went away halfway through the first season.
• Color Motifs: Blue. It's his favorite color. His main outfit is mainly blue. And it represents his heroic nature and Only Sane Man tendencies.
• The Conscience: To everyone, especially in later seasons, he serves as a voice of reason trying to warn them against making bad decisions.
• Dead Guy Junior: He was named after his mother Stella's late father. Craig Bartlett subsequently revealed that he's actually named for both of his grandfathers; his middle name is Phillip, though Phil is still alive.
• Decoy Protagonist: Somewhat. Arnold does have some subtle character development over five seasons, but it's Helga who has the clearest character arc, and in some crucial moments does most of the work that Arnold inadvertently gets credit for.
  • In "Arnold's Christmas" Arnold tries and fails to reunite Mr. Hyunh with his long-lost daughter, and it's Helga who saves the day.
  • Similarly in "The Jungle Movie" Arnold actually does very little to advance the plot, and Helga again has to be the hero. In the end, it's she who activates the machine that cures the Greeneyes and Arnold's parents of the Sleeping Sickness.
• Depending on the Writer:
  • Arnold's attitude towards Helga. Either he's indifferent to her and ignores her bullying for the sake of keeping the peace, outright hates her and is almost as cruel to her as she is to him, or tries to be nice to her because he knows she's not truly as mean as she makes herself out to be and hopes that his kindness will encourage her to show her real kindness.
  • A variation of this trope in that each of the main voice actors to play Arnold had a different take on him:
    • Toran Caudell's Arnold is by far the most prone to flights of fancy; he's also a lot less of a busybody than later Arnold portrayals and tends to just go with the flow - he's the most easily influenced (and corrupted) of the Arnolds as well.
    • Phillip Van Dyke is a good "middle ground" Arnold, but he's also less ambitious or driven than the others and mostly lacking in guile, definitely the most innocent of the Arnolds (the fact that he lacks a love interest for most of Van Dyke's tenure helps).
    • Spencer Klein plays Arnold the way that most of the fandom tends to remember (and depict) him: he's the most serious of the Arnolds, and the most romantic and sensitive (witness his approach to Lila vs. how Caudell's Arnold approached Ruth). He's the one who by far shows the most interest in Helga ("Dinner for Four", "Married", and "Arnold Visits Arnie" all happened during Klein's tenure, plus The Movie), and he's also the most goody-goody of the Arnolds - "Deconstructing Arnold" wouldn't have worked as a season 1, 2 or 3 episode.
    • Alex D. Linz didn't play Arnold for long, but what little we see of him is a drastic shift from previous Arnolds. He's similar to Caudell's Arnold in that he is back to behaving like a normal kid^note Perhaps as an attempt to de-Flanderize him, but with a few added layers, such as being a surprising mischievous streak - at least when it comes to Helga, flirting with her in an almost Trollish manner. The fact that Linz's appearances as Arnold take place after Helga confesses her love to him in Hey Arnold! The Movie, this may have something to do with the shift.
    • Mason Vale Cotton's Arnold in The Jungle Movie is less a deliberate rejection of Klein's take on the character (as Linz's was) and more a distillation. He's back to being (mostly) serious but he's less of a goody-goody (probably because he's too busy with his own plot to meddle in everyone else's). He has more of the Van Dyke childlike innocence to him, but also definitely has the most determination of them all, and although freaked out by Helga's advances at first, he eventually comes to terms with them and reciprocates, completely dropping the bizarre trolling-flirting combination he briefly employed when Linz voiced him. Despite returning her feelings, he's still more tentative with Helga than Klein's Arnold would have been - letting Helga initiate the kiss instead of kissing her himself, although stepping forward and leaning in to at least give her the go-ahead.
• Determinator: Arnold possesses strong will and believes that all problems are temporary.
• Dogged Nice Guy: When he realizes that he really does like Lila in a romantic way, Lila refuses to reciprocate his affections because she realized she never truly "liked-liked" him. He eventually gives up on her following the events of "Timberly Loves Arnold".
• Embarrassing Nickname: "Football Head". He doesn't make a big deal out of it, but it's obvious that he hates being called that.
• Embodiment of Virtue: Frankly, Arnold demonstrates all of the Seven Heavenly Virtues (with the possible exception of chastity), but the three virtues that define Arnold as a character are kindness, patience, and charity.
  • Kindness. Arnold's kindness and generosity is extended to every citizen of Hillwood, adult or child, friend or foe. Even if his kindness is not reciprocated, it's very rare for Arnold to retaliate without patience.
  • Patience. Arnold is always willing to help people in need, no matter how long it takes, how much work he has to put in, how irritating the person is, or if the situation is resolved in the exact way he'd like it to. This virtue extends to his participation in sports, as he'll insist on finishing a game even if the odds are stacked against him.
  • Charity. Arnold is a giver. As long as he's capable of doing so, Arnold has no problem helping people resolve their issues.
• The Everyman: In the later seasons, he became rather generic. The movies, along with "April Fool's Day" and "The Journal" would rectify this.
• Even the Loving Hero Has Hated Ones: After the public humiliation that Iggy put him through in "Arnold Betrays Iggy", Arnold ended his friendship with Iggy, and later episodes show that it stuck.
• Everyone Has Standards: As forgiving as Arnold is, his forgiveness and compassion do have limits.
  • Mainly whenever he's dealing with Oskar, Arnold will be pushed past his breaking point and call Oskar out for being a hopeless, lazy loser. Normally, it's Oskar knowing that he managed to get Arnold to lose faith in him that he finally realizes just how horrible he is.
  • Arnold can only tolerate so much of Helga's bullshit before he snaps, such as in "Girl Trouble" where he threw yellow paint on her after constant torment during an art project. It even makes Helga instantly regret her actions and have an (albeit comical) My God, What Have I Done? moment.
  • In "Weird Cousin", when Stinky keeps rubbing in the fact that Lila prefers Arnie instead of Arnold, Arnold tells Stinky to shut up.
  • But the biggest example comes from "Arnold Betrays Iggy," when it's only after trying to do everything he can to gain Iggy's forgiveness for leaking his secret (which wasn't even his fault, but Sid and Stinky's) and humiliating himself in front of the whole city does Arnold sever ties with Iggy; the next day, Iggy has realized that Sid and Stinky were the true culprits and tries to make amends with Arnold, but by that point, Arnold refuses to even give him the time of day.
  • Despite being nice towards everyone, he can't stand Campfire Lass as he thinks she's irritating and faking her accent.
• The Face: Among his circle of peers, he's the most sociable and problem-solving.
• Fatal Flaw: When a girl shows no interest in him, he refuses to take "No" for an answer and keeps pursuing them, refusing to give up hope that she'll change her mind. Lila has to consistently tell him she doesn't romantically like him and, while he's a good guy she generally likes, he has no romantic shot with her.
• Flanderization: He started out as a good-natured kid who sometimes made mistakes, but as the seasons went on, he turned into an incorruptible advice-giving saint who was almost never wrong and could do almost anything. Or, as put by Mr. Enter, he "became basically Jesus". He was de-flanderized in the movies and the last two episodes.
• Four-Temperament Ensemble: The Phlegmatic. He's a people person and also coy at times.
• Friend to All Living Things: Arnold's compassion extends to animals as well, as shown in "Field Trip" and "Big Caesar".
• Generation Xerox: In "Girl Trouble," it's revealed that his grandparents had a relationship very similar to the one he has with Helga when they were younger.
• Girl of the Week: Although some crushes have lasted through at least a season (Ruth McDougal and Lila Sawyer), he's had minor crushes not far in-between, like Maria, a sixth-grader, Miss Felter (a substitute teacher), Olga Pataki and Summer, an aspiring actress who's at least a couple years older than him.
• Given Name Reveal: His mysterious surname is finally revealed in The Jungle Movie when he signs his passport. Turns out it was not the first time we heard it.
• Good Is Not Soft: As nice and helpful as they come, but won't hesitate to call someone out for their misdeeds when they make him mad. He'll also stand up for others when they are in danger.
• Hair of Gold, Heart of Gold: Spiky, blond hair + Nice Guy + All-Loving Hero = Arnold.
• Hairstyle Inertia: He's had that weird spiked hairdo since he came out of his mother's womb.
• Handshake Substitute: He has a secret handshake with Gerald - both would either link their hands and wiggle their thumbs or hold their hands next to each other and wiggle their thumbs.
• Happily Adopted: Played with: while his grandparents have taken him in and raised him as their own, and he's happy under their parenting, he still longs to find his mom and dad. And in The Jungle Movie, he, Gerald, and Helga do exactly that.
• Happily Ever After: Word of God confirms that Helga and Arnold eventually fall in love and get married as adults. They are promoted from Word of God to Canon at the end of The Jungle Movie.
• The Heart: His kindness and determination are what's keeping the town together.
• Heartwarming Orphan: Deconstructed. Arnold is one of the nicest characters in the series, but him being an orphan is a very sore spot for him.
• Heroic BSoD: In the episode, "Parents Day", when Big Bob makes fun of his missing parents by calling him an "Orphan Boy", Arnold gets depressed for the rest of the day until he goes to sleep and realizes how much his grandparents have filled the gap his real parents left.
• Heterosexual Life-Partners: With Gerald; they have been best friends since preschool and have a secret handshake.
• Hidden Depths:
  • Arnold appears to be gifted with artistic talent, as mentioned in "Part time Friends" and "Rich Guy".
  • According to "The Aptitude Test", Arnold would make an excellent ambassador to a foreign land.
  • Arnold appears to be a good tango dancer, as shown in "April Fool's Day."
  • In "The Sewer King" Arnold is shown to be extremely adept at playing chess, which was one of the first of many instances that showcase his keen strategic abilities.
  • Arnold has impressive skills in video editing as seen in the episode "Freeze Frame" and Hey Arnold!: The Movie.
• His Name Really Is "Barkeep": Grandpa's pet name for him is "short man". Word of God, and later The Jungle Movie, revealed that "Shortman" is Arnold's actual last name.
• Honor Before Reason: "Full Moon". Arnold is a witness to Harold, Sid, and Stinky's prank of mooning Principal Wartz. Because Arnold won't lie, he admits he knows what happened and saw it, but he won't tell them because he's not a rat. After receiving four weeks of detention in which Wartz repeatedly shows propaganda against thinking that mooning is funny and even tells him why he should rat out the culprits even though it would make him a Bully Magnet, Arnold still refuses to tell because "He's not a rat".
  • Though Wartz' anecdote of how he once ratted out his classmates and spent the rest of his youth being a social outcast probably helped Arnold stick to his principals.
• Humiliation Conga: Happens to him in the episode "Arnold Betrays Iggy", when he was forced to wear bunny pajamas in front of the entire town, who all laugh their tails off at him (including the adults.)
• I Just Want to Be Normal: On his journey to find his long-lost parents, he discovers that the elusive Green-Eyed people believe him to be a messianic chosen one destined to save their civilization. This never goes to his head, nor does he appear terribly comfortable with the idea. He just wants to find out what happened to his parents and go home.
• Iconic Item: His little blue baseball cap is one of the most well-known things about him.
• Iconic Outfit: Arnold's famous for wearing a red plaid shirt (that's not a kilt), a blue sweater, jeans, and a tiny blue baseball cap.
• Ideal Hero: High morals, Nice Guy, and willing to help anyone, even those who don't deserve it and treat him like a used napkin.
• Improbable Hairstyle: How does his spiky hair manage to stay in place like that? He is never shown to use any products to make it do so.
• Incorruptible Pure Pureness:
  • Bob Pataki tried to bribe Arnold into throwing the spelling bee so that Helga could have an easy win. Arnold threw the bribe away and proved his mettle.
  • Arnold is described as such in The Jungle Movie by Gerald and he certainly lives up to it. He is kind to almost everyone, from the local Alpha Bitch to the meanest of jerks and they can never make him falter. On top of it all, he has changed lives of others with kindhearted advice.
• Informed Attractiveness: Zigzagged. Helga, as she constantly swoons over Arnold in private, she tends to mention how handsome she thinks he is. While that may be sort of true considering that he looks quite normal compared to the rest of the quite detailed and slightly ugly cast in the cartoon, yet he has quite a football-shaped head that PLENTY of characters throughout the series comment on, which would probably count as being ugly in real life. It's likely that his kindly nature caused Helga to subconsciously link his appearance with attractiveness.
• Instant Expert: While it wasn't ever stated how long his martial arts lessons took, he became a Bruce Lee tier Badass without taking a lifetime of training.
• Intergenerational Friendship: With the adults of his grandparents' boarding house. He even refers to them as his family on a few occasions. He's also pretty close to Coach Wittenberg (who asked Arnold to be the best man at his wedding) and Dino Spumoni.
• I Will Find You: His primary goal in The Jungle Movie is to find his missing parents. He succeeds. And despite an All Just a Dream tease towards the conclusion, it was all real.
• Jerkass Ball: Even Arnold can be genuinely mean-spirited sometimes. Examples of this are:
  • He two-times Ruth and a disguised Helga in the Valentine's Day episode, peaking when Helga made a very sincere love confession and he responds by going back to his (failing) date with Ruth.
  • "New Teacher", where he participates in the hazing of Mr. Simmons along with the rest of the class (though he did feel remorse for it like his friends did.)
  • "Egg Story", where he's uncharacteristically frigid to Helga even though she was actually trying to be nice that time. Though given their history of her bullying him (and their shaky partnership on a science project in "Biosquare"), he might assume she was going to eventually.
  • During the fancy-dress party in "Helga's Masquerade" Arnold and Helga get along quite well, albeit only because Helga was emulating Lila at the time, up to and including resembling Lila. When she felt confident enough to change back into her pink dress, Arnold lost all interest in her, stating that he only felt attracted to her because she resembled the girl he's really keen on. For such an empathetic kid that's pretty heartless.
  • "Timberly Loves Arnold", where he uses Timberly's crush on him to get closer to Lila (who finds Arnold "ever so sweet" for paying attention to Timberly). He does eventually feel guilty about it and apologizes to both girls.
  • "April Fool's Day": Both Arnold and Helga were massive jerks to each other in this episode. Arnold at first tries to ignore Helga's constant practical jokes at his expense, but the last straw was making him sit down in a plate of chocolate pudding, causing him to retaliate. While it's understandable that he wants payback, it's the way he retaliates that makes him a jerk. He calls Grandpa and asks for his gag gift box that, when opened, would temporarily blind the person who opened it. He gives it to Helga, claiming it's a belated birthday present (coincidentally, her birthday was the previous week, the unspoken point is him perhaps knowing about Helga's feelings for him at this point, and that they would blind her judgment and make her fall for such an obvious joke). He again feels guilty for his actions (he didn't know it would cause blindness) and spends the rest of the episode putting up with her torture until he finds out she's faking the blindness. Then he aggressively dances and flirts with her before tossing her into the pool as payback.
• Karmic Jackpot: Arnold's exploits involve him helping out nearly everyone in town. A highlights reel of this is what wins him a plane ticket to San Lorenzo, and, by extension, a chance to find his parents.
• Kid Hero: Arnold is a nine-year-old boy and has saved the day on more than a few occasions and regularly helps improve the lives of those around him.
• Likes Older Women: Lila is the only one of Arnold's crushes who wasn't older than him. He even has a brief crush on his subsititute teacher Miss Felter. Though Arnold will eventually end up with Helga, who's the same age as himself.
• Living Emotional Crutch: Helga outright says she would probably go crazy if it weren't for Arnold.
• Love Epiphany: Subverted. Arnold falls in love with "Hilda" in a dream sequence, who is a manifestation of all the good qualities that Helga tries to hide about herself. This suggests that, on some subconscious level, Arnold does share her feelings even if he doesn't realize it.
• Love Revelation Epiphany:
  • After Helga gives Arnold a second Love Confession (in The Jungle Movie), Arnold has a private talk with her about their history and how, despite her having picked on him before, he always wondered if she did it because she actually loved him. He mentions how while he's seen her be mean, he's also seen her be kind and it was her actions that let him find his parents again. The moment culminates in their first mutual and romantic kiss.
  • If we can pinpoint it to a precise moment, it's when they're hanging from the cliff and they look over at each other◊ - and it's obvious Arnold is finally really looking at her for the first time (They exchange the exact same gaze - and we know Helga loves Arnold.)
• Loved by All: Arnold’s kindness and helpfulness over the years have made him the most beloved kid in his neighborhood. Come Hey Arnold! The Jungle Movie people who helped over the help show a video of how he has helped them, so he could win a trip to San Lorenzo.
• Loving a Shadow: His interest in Ruth is completely superficial, but also in general, he easily falls in love without actually knowing his beloved. He at least gets to know Lila, but fails to recognize how little chemistry they share or take the hint that no matter how persistent he may be, she just doesn't feel the same way about him.
• Luminescent Blush: He blushes a lot in "Timberly Loves Arnold", where Gerald's little sister has a crush on him. Gets this a bit as well in "Arnold Betrays Iggy", when he thinks back to Iggy wearing bunny pajamas. Also gets it at the end of "Arnold Visits Arnie" when he realizes that he forgot to change out of his own teddy bear covered pajamas before going outside to meet his friends.

M-W

• Magnetic Hero: Due to his helping and kind nature, Arnold is genuinely liked by everyone in his neighborhood.
• Man in a Kilt: Averted. Many people in and out of universe think that Arnold is wearing a skirt/kilt below his sweater. It's actually a long, un-tucked plaid shirt, as noted by his plaid collar. He even pulls off his sweater in some episodes to confirm this. Perhaps in response to this trope, his redesign for The Jungle Movie (as seen above) makes it more obviously an un-tucked shirt.
• Masculine Girl, Feminine Boy: The Feminine Boy (gentle, soft-spoken, All-Loving Hero) to Helga's Masculine Girl (violent, aggressive, Loving Bully).
• Master of the Mixed Message: Even though he's normally neutral towards Helga (or in some cases is just as mean to her as she is to him), there are some episodes that imply that Helga's feelings towards him are not one-sided. "Arnold's Valentine" and "Helga's Masquerade" show us that he does enjoy spending time with Helga when she's not being mean to him and he flirts with her in at least two episodes ("Dinner For Four" by playfully spraying her with water while winking and again during their tango in "April Fool's Day"). In "Married", his saying that he hates Helga and will never ever marry her sounds more like denial than an acknowledgment of the fact. The strongest evidence would probably be his dream in "Arnold Visits Arnie" where he falls for a girl named Hilda who is a nicer, slightly prettier version of Helga, implying that he would like the "real" Helga if she would allow her true self to come out. Since it's been officially confirmed by Bartlett that the two end up together, he definitely feels something.
• Maybe Magic, Maybe Mundane: It might've just been a coincidence, but Arnold appeared to stop a volcanic eruption and silence all of nature when he was born. This was enough proof for the Greeneyes to believe him to be some kind of demigod chosen one. Regardless of how true this is, it does effectively underscore Arnold's thematic purpose on the show as the center of balance and the peace bringer.
• Mean Character, Nice Actor: He ended up being cast as the villain of the titular play in "Eugene, Eugene", and did a surprisingly good job at it.
• Meaningful Name: It was confirmed by Craig Bartlett (and eventually made canon in The Jungle Movie that his last name is Shortman. He's one of the shortest kids in his class, being shorter than a good number of his friends such as Gerald, Helga, Sid, Lila, Eugene, etc.
• Morality Chain: He serves as a moral compass to any character who's on the edge of making an immoral decision, especially Helga.
• Morality Pet: Arnold is this to Oskar. Like the rest of the adults at the boarding house, Oskar has a soft spot for Arnold. However, Oskar Kokoshka is also a colossal liar, moocher, lazy bum, and overall Jerkass, and it takes something incredibly drastic for him to want to change. In most of his A Day in the Limelight episodes, it usually happens when he finally drives Arnold so high up the wall, when Arnold is trying to help Oskar be a better person. Oskar usually makes up excuses to Arnold for not working to improve himself or lies to Arnold to get out of work. Arnold loses faith in Oskar and tells him that he's done trying to help him and stomps off, leaving Oskar full of shame. Oskar then makes a genuine effort to make it up to Arnold and show that he can improve himself, restore Arnold's faith in him, and demonstrate that Oskar does care about Arnold for all his faults.
• Mr. Imagination: The early episodes had a lot of focus on Arnold's daydreams and flights of fancy, a trait carried over from the original clay shorts and the Sesame Street shorts. Later episodes dropped this trait, though from time to time popped up again.
• Never Bareheaded: Unlike Harold and Sid, who are shown hatless several times, Arnold is almost never seen without his little blue baseball cap, even wearing it in settings where he shouldn't be allowed to. The only time he's seen without it for a lengthy period was when he temporarily lost it in "Arnold's Hat".
• Nice Guy: His defining character trait. Even when he's not the focus of an episode, he'll occasionally be the only one who won't make fun of the episode's protagonist.
• Nice Mean And In Between: Of the main trio in the show, he's the Nice to Helga's Mean and Gerald's In-Between; he's an All-Loving Hero who is willing to help anyone out and is highly optimistic.
• No Full Name Given: A Running Gag in the series is that Arnold's last name is never revealed. The creator later confirmed that his last name is Shortman and his last name finally makes its first onscreen appearance in The Jungle Movie. This gets lampshaded yet hand waved in one episode.
  Announcer: And the winner is...Arnold...hm. The last name appears to be smudged.
  Stinky: That must be you, Arnold, on account of you're the only Arnold in the entire school.
• No More Lies: In the episode "The Big Scoop," Arnold and Helga argue about how to run the school newspaper. Helga wants to tabloidize it and run big juicy stories that run deeper than the truth, while Arnold wants to stick to the facts and tell the truth. Helga eventually left with her best friend Phoebe to make her own newspaper. Helga finds success in her newspaper by posting fake stories and half-truth stories, while Arnold struggles to compete with her by just posting the truth. Helga is shown to be willing to steal Arnold's stories and add lies to them. Eventually, Arnold and his best friend Gerald heard that Helga planned to post a story that said the school would be torn down and an amusement park would be built in the school place. Arnold and Gerald investigated and asked Principal Warts, who revealed that while the school was going to be torn down because walls were going down, no amusement park was going to be built in its place. Walls would be torn down because they would add to the school, building more classrooms. After getting a quote that confirms Principal Wart's story, Arnold and Gerald posted the story, and when Helga tried to post her version of the story, their classmates angrily said that's not what Arnold's stories said, and with Principal Wart's confirmation no one believed Helga story. And when Arnold tells Helga that no one believes anything in her paper, she tries to save face by telling more gossip and reducing her paper's price, only for her classmates to say no more lies. When Helga asks why everyone is so upset, she wants to tell good juicy stories that delve deeper than the truth; Arnold answers that she pushed the truth too far. This causes Helga to finally close down her paper and rejoins Arnold's paper, reporting the weather.
• No-Respect Guy: As shown in "Deconstructing Arnold", his classmates, until the end, don't realize how much wise impact he has on their decisions until after they told him to buzz off with his goody goody righteous personality and he subsequently obliged.
• Not So Above It All:
  • In spite of how selfless and wise Arnold became in the later seasons, there were still times that showed he wasn't as saintly as you'd think. He keeps going after Lila and hoping she'd reciprocate his crush despite how often she explains to him she doesn't like him that way, and at one point he was willing to take advantage of Timberly's crush on him in order to spend more time with Lila.
  • In "Jamie O In Love," Arnold is the one who is more willing to use Jamie O to get stuff than Gerald is, even after seeing what an emotional wreck Jamie O's toxic relationship is turning him into.
  • In episodes where he's Out of Focus, he'll sometimes join in with his peers when they gang up and do something mean. He participated in the hazing of Mr. Simmons and didn't feel any sympathy until after the poor guy had broken down, which he quickly shrugged off; he took part in Harold's pranking of the girls' sleepover (to be fair it was a harmless jumpscare, but still more immature than he normally acts); and he entertains the idea of treating the kids a grade lower than him the same way the 5th graders treat him now. If there's a group shot of the kids laughing at something cruel, he's usually seen joining in.
  • Even if he would rather they tell the truth themselves, Arnold isn't The Stool Pigeon (or a "rat" as he puts it) and would never tell on his friends for doing something wrong unless it was serious or life threatening. Even in situations where they're actively doing something awful he highly disapproves of, Arnold prefers encouraging others to come clean over revealing the truth himself, and dislikes the idea of being thought of as a "rat" by his friends.
• Oblivious to Love: Arnold seems incredibly oblivious when it comes to figuring out Helga's crush on him. Seriously, he buys any flimsy excuse Helga comes up with to cover up her secret. The one time he didn't buy her excuses was in the movie. And, even then, after Helga flat-out declares she loves him and kisses him, he still has a hard time believing it and asks, "I'm confused. Did you just say you... love me?"
• Official Couple: Finally reciprocates Helga's feelings by the end of The Jungle Movie and becomes a real couple with her.
• One Head Taller: Gender-flipped with Helga. Minus the spiky hair, he is shorter than Helga.
• Only Sane Man: Amongst his eccentric classmates, he serves as the one to prevent their unstable emotions, though Gerald isn't that far behind.
• Orphan's Ordeal: He can shrug off most insults, but calling him an orphan will cut him deep. Real deep. Even Helga objects against the idea. And whenever the anniversary of his parents' disappearance approaches, he goes melancholy and it's the only time of the year he wants to be left alone.
• O.O.C. Is Serious Business:
  • Arnold not forgiving Iggy for the hell he was put through in "Arnold Betrays Iggy". You know you've screwed up big time when Arnold doesn't forgive you. The episode "Dino Checks out" implies that Arnold still has not forgiven him.
  • Usually happens whenever his parents are brought into the picture.
    • "Parents Day" has Arnold rejecting Phil's (often fictitious) bedtime stories about his parents. Phil automatically asks Arnold if he's sick.
    • "The Journal" takes place on the anniversary of his parent's disappearance. The normally nice, cheerful Arnold is reduced to a depressed wreck who wants to be left by himself. It's then when he decides to give up hope on his parents ever returning. He packs up all of his mementos of them, even his hat, which shocks Phil to no end. Thankfully, he finds the eponymous journal which gives him (some) of the answers he desires.
  • Played for laughs in "Weird Cousin" when Stinky goes on and on about Arnold's cousin Arnie hooking up with Lila.
    Arnold: (gritting teeth) Stinky... shut up.
  • The fact that, in The Jungle Movie, Arnold actually starts crying (something he never did before in the series) after his group is imprisoned by Lasombra and it looks like he'll never find out what happened to his parents, which shows just how far past the Despair Event Horizon he is.
• Out-of-Character Moment: Helga seems to be the one person capable of causing Arnold to snap out of his endlessly kind and patient nature.
  • In "Girl Trouble" after she dumps a can of paint on him he instinctively retaliates, to the shock of Helga, Mr. Simmons as well as Grandpa Phil.
  • In "Egg Story", when he is partnered with Helga, he doesn't even give her a chance to speak before unloading on her, declaring he'd rather work with anyone else and saying some other uncharacteristically cruel things, showing that he has had enough of the way she treats him.
  • By far the most notable examples of Arnold acting out of character occur in "April Fool's Day." First, after being pranked by Helga one too many times he preys on her weakness (this episode happens after the first movie, thus Arnold knows how Helga really feels about him at this point) and pranks her back with Grandpa's flashing gift box, which causes her to temporarily go blind (though Arnold didn't know it'd cause actual blindness). Later, after finding out that she has been faking her blindness and using him as her slave, he abruptly starts very aggressively flirting with her to throw her off her guard and ends up throwing her into a swimming pool. This side of his personality has been affectionately dubbed as "Dark Arnold" by fans.
• Out of Focus: Most episodes of Seasons 4 and 5 focused on developing the supporting characters, with Arnold himself largely Demoted to Extra. Some random character would face a problem, and at some point, Arnold casually walked up to them, gave them a piece of advice, and disappeared for the rest of the episode. You could take out him out of the episode and there’d probably be little to no difference.
• Phrase Catcher:
  • Every so often, characters say the show's title, "Hey Arnold!" to him.
  • Gerald often calls Arnold "a bold kid".
  • And then of course there's Helga's "move it, Football head!" and its variants.
• Pink Girl, Blue Boy: Blue Boy to Helga's Pink Girl. He wears a blue hat and a turquoise/teal (a blueish-green color) sweater and Helga wears a pink bow and pink clothes.
• The Pollyanna: Arnold remains optimistic in spite of his hardships. It's one of the qualities that Helga admires most about him.
• Precocious Crush: In season 1, he had a crush on Ruth P. McDougal, a sixth-grader. In "6th Grade Girls", he develops a crush on yet another sixth-grader. In "Crush On Teacher", a season 2 episode, he develops a crush on his substitute teacher, Miss Felter. In "Summer Love" he has a brief romance with Summer, who's also a few years older than him. He’s even shown to have a crush on Olga.
• Protagonist Title: His name is part of the show's title and he's the main character.
• Punny Name: He's a short (young) man with the surname Shortman. In fact, Steely Phil uses this to turn his surname into a nickname.
• Raised by Grandparents: Since he was a baby, Arnold was raised by his paternal grandparents after his parents went missing. It is later revealed that he has at least one maternal aunt or uncle (the parent of his cousin Arnie) who exists only by inference; he or she is never seen or mentioned. Either way, Phil and Pookie obviously took precedence.
• The Reveal: After spending the series with his last name unknown, The Jungle Movie reveals it actually was "Shortman" and we knew it all along- it wasn't just an Affectionate Nickname from Grandpa Phil, but his real surname. Phil has Arnold fill out a passport and requests he write his name on it as it appears on his birth certificate. Arnold's middle name, however, by that line of reasoning, is apparently nonexistent.
• Rightly Self-Righteous: Arnold manages to be morally superior to just about everyone else without being obnoxious by going about it in his own gentle, humble, and down-to-earth way.
• Shorter Means Smarter: One of the shortest kids in his class and also one of the smartest.
• Strong Family Resemblance: He gets his facial looks and oblong-shaped head from his mother, but his blond hair is from his father.
• Strong Girl, Smart Guy: With Helga. While she's quite smart, Helga is mainly known as a Cute Bruiser bully who does not hesitate to use physical force, while Arnold is mature, never resorts in violence, and gives advice to everyone.
• Suggestive Collision: He and Helga run into one another a lot throughout the series, but in The Jungle Movie, when he saves her from a "booby trap" by tackling her, he kind of... cops a feel. Probably accidentally. It does not go unnoticed by Helga.
• Supporting Protagonist: In later seasons, many of the episodes focused on Arnold's classmates, roommates, neighbors, or anyone else. He's still involved, but the episodes' stories don't focus on him. It isn't until the first movie that the focus is shifted back to Arnold.
• Technology Porn: His bedroom, which boasts a glass ceiling and any number of implements operated by remote, including a fold-out couch. He also has a personalized alarm clock of himself that shouts "Hey Arnold!", "Hey Arnold!".
• Time-Shifted Actor: Rusty Flood voiced the young Arnold during the flashbacks in "Parent's Day" and "Helga on the Couch." Goes to show that even though the young actor who voices Arnold may be good at his role, he is still just a prepubescent boy who is susceptible to voice changing.
• Tiny Schoolboy: He is one of the shortest boys out of his group of friends and fits with the adorkable type.
• Took a Level in Badass: In "Mugged" where Pookie teaches him martial arts. He also Took a Level in Jerkass as the new power corrupted his mind.
• Tragic Keepsake: His baseball cap, which was given to him by his parents. When he loses it in "Arnold's Hat", he's determined to get it back and is utterly depressed without it. Arnold packing it away in "The Journal" shows just how serious he is about letting go and moving on with his life. At least until Grandpa Phil found Miles' journal (before looking at it, Arnold goes back to the attic to retrieve his hat.)
• Trauma Button: Whenever Arnold is reminded of his parents... it's not pretty. "The Journal" illustrates this best, showing that, whenever the anniversary of Miles and Stella's disappearance arrives, he spends the entire day depressed and wishing to be left alone.
• Tsundere: He seems to be a milder, benign male one towards his Loving Bully Helga. He denies the thought of liking her romantically and has lost his patience with her on more than one occasion, though he does try being nice to her and tolerates her bullying to an extent, not to mention there are some implications that he likes her back, but isn't ready to accept it. By the time that The Jungle Movie comes around, he comes to terms with it and gives Helga a kiss.
• Unwitting Instigator of Doom: Arnold serves as this to Eugene. Although Arnold means Eugene no harm and feels bad whenever something bad happens to him, he ends up doing something that leads to something bad happening to Eugene anyway. In "Eugene's Bike", Arnold accidentally knocks Eugene's bike into the street when he stops to tie his shoe, resulting in the bike being run over and destroyed by a street sweeper. When Arnold tries to fix the bike, he accidentally forgets to install the brake cable, resulting in Eugene being unable to stop and getting hospitalized when he crashes into an open car door. When Arnold comes to visit him, the 9 on Eugene's hospital door becomes a 6, resulting in Eugene getting his tonsils and spleen removed. When Arnold feels guilty about getting Eugene hospitalized, flashbacks show that Eugene was accidentally knocked off a seesaw at daycare, had a crab accidentally tossed onto his head, and got his finger stuck to his lips when he accidentally tasted Arnold's paste instead of his frosting. When Arnold tries to give Eugene a grand day out together, things get worse from there. Eugene falls down an open manhole, gets hit by a foul ball, chokes on a hot dog, hit in the eye with it when Arnold gives him the Heimlich Maneuver, and falls into the river when he tries to look out a tower viewer.
• Vitriolic Best Buds: He and Helga have this dynamic, prior to her confessing her feelings. They bicker and argue, but often confide in one another and begrudgingly enjoy hanging out.
• Wide-Eyed Idealist: Almost always believes in the best possible outcome, even when he should know better. Subverted as he’s almost always proven right in the end.
• Wise Beyond His Years: He's much smarter and wiser than a nine-year-old should be, to the point that everyone on the show, including adults and authority figures, have come to him for advice.
• Wrong-Name Outburst: He accidentally calls Helga "Lila" in "Helga's Makeover". Considering that Helga looked and acted exactly like her, it's quite understandable why he would make this mistake.