Airdate: October 21st, 1996
Both episodes start off with Arthur and his family celebrating the 1st-birthday of his youngest sister, Kate, with the family also videotaping it. Part-1 ("Arthur's Baby") focuses on how Arthur dealt with his mom being pregnant with Kate and waiting for the new baby to arrive and then what he went through once Kate finally came home—Part-2 ("D.W.'s Baby") focuses on what D.W. went through after Kate was born and how she adjusted to being an older sibling.
Both episodes contain examples of:
- Afraid to Hold the Baby: In the episode "Arthur's Baby" (and "D.W.'s Baby," which reuses this clip), Arthur doesn't think that his new baby sister Kate likes him. When his mother instructs him to hold Kate for a bit, he is very nervous about it. Kate starts crying, and Arthur's sister D.W. helps him take care of Kate. Arthur starts liking Kate after he burps her and causes her to feel better.
- Another Side, Another Story: We see both Arthur and D.W.'s perspectives on Kate coming home.
- Birthday Episode: The prologues to each segment take place on Kate's first birthday.
- New Baby Episode: Each segment is about Kate's birth and Arthur and D.W. adjusting to having a new baby sister.
- Self-Serving Memory: Invoked by both Arthur and D.W. at the beginning of each segment. Arthur says he misses when Kate was a newborn, and D.W. reminds him that he and Kate had a rocky start. Meanwhile, when D.W. says little sisters are better than brothers, Arthur reminds her that she didn't always think that.
- Stock Sound Effects: Kate's crying sounds very different in both episodes, sounding louder and more intense than her usual stock crying sound heard numerous times throughout the series. Though it could be justified in that the scenes of her crying are when she was a newborn, though her usual stock laughing sound effects still there.
- Unreliable Narrator:
- Each Cold Open has a different kind of cake for Kate's birthday; in Arthur's segment, the cake is a slice, while in D.W.'s segment, it's a cupcake.
- Arthur's segment misses out on some things that D.W.'s picks up, and vice-versa: Kate's baby monitor getting set up, for example, or Kate crying when Arthur holds her.
- In the sequence where Arthur burps Kate, Arthur's segment plays it out as D.W. having things perfectly under control until Kate spits out her pacifier; she wiped the pacifier with a napkin and gave it to Kate. D.W.'s segment plays it out as her messing up by cleaning the pacifier but dropping it again and Kate starts crying with Francine and Buster visiting.
- Arthur's segment ends with D.W. happily seeing that Kate is kissing Arthur. In D.W.'s segment, she growls angrily about it under her breath.
Arthur's Baby contain examples of:
- Accidental Hero: Arthur stops Kate's crying by gentle patting her back and staying calm. This causes her to burp, which was the problem.
- Actually Pretty Funny: Buster jokingly draws a picture of Arthur "babysitting," showing him sitting on a baby. Arthur is worried but actually admits it's amusing.
- Brainy Baby:
- In the prologue, when Arthur tells the viewers that everyone was a baby once, an infant version of Mr. Ratburn is seen writing math problems on the wall in an Imagine Spot.
- Buster suggests that Arthur could teach a baby to do his homework. Cue an Imagine Spot where Arthur is giving instructions to start on a report on Magellan while chilling in bed, and a baby with his glasses gives an Aside Glance in the middle of math problems.
- Character Development: Arthur and Kate get this mutually:
- Arthur spends much of the episode worried about how a new baby will change his life. When D.W. hands off a crying Kate to him, he stays calm and pats her back, trying to figure out what she's trying to tell them.
- Meanwhile Kate starts by crying every time Arthur even tries to get close to her. When he burps her, she quiets in his arms and starts kissing him.
- Characterization Marches On: Most of Arthur's friends except Buster are actually mean to him after hearing that he's going to have a new baby sibling, intentionally causing Arthur to worry with telling him things like babies crying loudly nonstop, the smelly diapers, and never sleeping again. Buster innocently brings up the the possibility of his mom having twins or more. Compared to how if this occurred in one of the much later seasons, they would've most likely instead been happy for him (particularly Binky and Francine, who both greatly softened up as the show went on.)
- Cold Open: This one features Arthur's Imagine Spot of Buster, Mr. Ratburn, and his parents as babies.
- Cuteness Proximity: Francine and Buster coo over Kate, who is happily sucking her pacifier.
- Early-Installment Weirdness: In the teaser, Mr. Ratburn's first name is Emil. Later episodes would give his name as Nigel.
- Mass "Oh, Crap!": Played for Laughs: the Reads all Gasp! when Kate grabs a piece of her birthday cake and smashes it against her face.
- Oh, Crap!: Arthur has this reaction when he finds out his mom is pregnant, and he has it every time Kate cries in front of him.
- Sarcasm Mode: Arthur gives a dull, unenthusiastic "Yahoo" after hearing that he and D.W. have a little sister and not a brother.
- Sibling Rivalry: The episode properly starts with Arthur and D.W. fighting over the last grape in a bowl. D.W. wins it with some quick thinking.
- Tempting Fate: After D.W. gets the last grape, Arthur says the world would be better if all "little sisters" were removed. In this episode, he gets another sister.
- This Is Reality: Buster suggests that maybe Arthur could either train the new baby to do tricks and earn money for him. Or the baby could do all the homework from Mr. Ratburn to give him a break. Arthur likes the ideas, but he points out life is not like that.
- Too Many Babies: When Buster asks Arthur what would happen if Jane had more than one baby, an Imagine Spot is shown where Arthur is surrounded by many infant siblings.
D.W.'s Baby
- Actually Pretty Funny: In the Cold Open, Arthur laughs on seeing the video of his first birthday, and his parents are teaching him to blow out the candle on his cake. Baby Arthur ends up sneezing it out and getting frosting all over his mother's face; as Arthur puts it as an older kid, "Hey, perfect."
- Batman Gambit: Grandma Thora humors D.W.'s wish to run away to Button Island by driving her there and talking about how she'll miss her. She then conversationally brings up that Kate will miss D.W. when she's older, because she'll have a mommy, daddy, and a brother, but no sister. D.W. is deeply moved by the very idea that Kate's life would be incomplete without her in it. This convinces her to go back home and take care of Kate.
- Be Careful What You Wish For: D.W. wants to be the sibling in charge of Kate. She thinks that she's going to get this power when her parents move Kate into her room. The problem is that Kate is crying incessantly at night, stinking up the room with her diapers, and unable to play.
- Cold Open: This one features Arthur looking at old family videos of his first birthday, and D.W.'s first birthday. Arthur as a baby sneezed on his candle, and D.W. waved out the candle while begging for presents.
- The Diaper Change: During the montage of D.W. sharing a room with Kate, Jane is seen changing Kate's diaper. The stench of Kate's diapers is too much for D.W. to handle, and when she tries to open a window to get some fresh air, Jane tells her to close it before Kate catches a draft.
- Didn't Think This Through: There's a reason why you don't move a baby into a sibling's room if they're a light sleeper and crying at all hours of the night.
- Failed a Spot Check: Jane fails to notice that D.W. has bags under her eyes from not getting sleep for several nights in a row thanks to Kate's crying. D.W. says she can't eat her cereal because, "my teeth are tired" and we don't see Jane's response.
- Go to Your Room!: D.W., taking the advice of the Tibble twins, tries to pin the blame on Kate for bad things that she did or others did, so her parents won't love the baby anymore and get rid of her. When David finds his new shoes in the dishwasher, D.W. immediately blames Kate, claiming that she saw her do it. David obviously doesn't buy for a second and sends her to her room, telling her that he'll be up in a few minutes to discuss it with her.Nadine: He said "discuss". You know what that means.
D.W.: Yeah. I'm in trouble. - Ill-Timed Sneeze: Arthur as a baby sneezed out his candle, as well as frosting all over his mother. As an older kid, Arthur says it's perfect.
- Infant Sibling Jealousy: Played straight only for D.W.—in part-1 and the beginning of part-2, it's shown that D.W. was initially very excited about being an older sister, especially once the baby turned out to be a girl instead of a boy. However, D.W. soon gets tired of having Kate around the house, due to her constant crying at night and stinky diapers. She tried to get Kate in trouble by blaming her for things she or somebody else did, and even tried to sell her at a Garage Sale for 50-cents (and then lowering it to 35). When she runs away to Grandma Thora's house, Thora reminds D.W. that when Kate grows up, she'll have a mom, dad, and brother, but no sister to take care of her. This quickly convinces D.W. to go back to her house and be the best big sister ever to Kate.
- O.O.C. Is Serious Business: Jane looks briefly angry at baby Arthur for sneezing frosting on her, when she's been mellow with all the kids as babies.
Granted, Arthur was her first baby, and it's possible she had yet to build up the patience and experience she has today. - The Runaway: D.W. decides in the climax to run away to Button Island and "live with monkeys" because she's tired of living with Kate. Fortunately, she goes to Grandma Thora to say goodbye and get a ride; as revealed by the end, David and Jane were worried sick about where D.W. went.
- Surprisingly Realistic Outcome: In the second act of the story, D.W. gets her wish of Kate sharing the same room as her, thinking she will get to spend more time with her. As she learns in the ensuing montage, being roommates with a baby isn't necessarily fun and games. Between Kate's constant crying and her diapers stinking up the room, the novelty quickly wears out for D.W. Also, building on the diaper dilemma, she can't even air out her room because it could let in a draft that could make her baby sister sick.
