After watching Batman foil his plan to assassinate Mayor Grange (a plot involving a bowl of chili and a gas-spewing fire truck) with the help of Batgirl, Joker becomes envious of the Dark Knight's new Kid Sidekick (insisting to Punch and Judy that they "aren't sidekicks, you're goons!"). Determined to get a Kid Sidekick of his own, he heads to a comedy club and confronts failed comedian (and Barbara Gorden's classmate) Donnie, insisting that the two aren't so different and insists that Donnie become his "apprentice." Donnie remains unconvinced until Joker pulls a practical joke on his teacher the next day as proof that he has the comedy chops to make people laugh. In the meantime, Batman and Batgirl's hero-sidekick relation isn't as healthy as it appears. Despite Batgirl's desire to be treated as a partner, Bruce is reluctant to take on a sidekick.
Joker takes Donnie to his hideout and the two brainstorm ideas. While Donny's first few ideas fall flat, he happens upon a Joker-worthy plot after Punch and Judy (upset at being passed over for promotion by a random kid Joker practically pulled off the street) spit a wad of gum at him: Fire giant gumballs at the Gotham police headquarters.
With a giant gumball cannon in tow, Joker, Donnie (now wearing a clown costume and calling himself Prank), Punch, and Judy disable the GCPD. Even Batman and Batgirl prove no match for the massive machine, with the former get trapped waist-deep in gum and the latter getting knocked out after getting distracted by the realization that Joker's sidekick is Donnie. Joker ties her to the front of the cannon and demands Donnie fire it. However, Donnie is unable to bring himself to execute her because he doesn't "get it," much to Joker's dismay ("You yank lever, gumball go boom! Goo everywhere, including Batgirl's! We laugh, they cry, WHAT'S NOT TO GET?!"). Joker fires the cannon himself, although not before Batman gets free and saves Barbara, and drags Donnie off. Fortunately, Barbara has planted a tracer on Donnie, and the Bats give chase.
An enraged Joker drags Donny back into their hideout, which is revealed to be inside the ACE Chemical Plant. Joker reveals his plan to dunk Donnie in the same acid vat he himself fell into, in order to fully complete his transformation into "crazy crime clown." The Bats show up just in time to stop Joker from throwing him in, and after a brief fight Donnie knocks Joker out with his own Extendo Boxing Glove. Batgirl wryly jokes that her strained relationship with Batman at least looks good in comparison to Donnie and Joker's.
Tropes:
- Actually Pretty Funny: The entire school (sans Barbara) are amused when Joker ties Donnie's teacher to a flagpole, which he uses as proof that he "knows funny."
- Annoying Laugh: Donnie. It’s how Batgirl realizes he’s Prank.Batgirl: That laugh... No. Way.
- Bad Boss: Joker, as per usual. He's extremely dismissive towards Punch and Judy and promotes some random kid over them because they're "goons," and then later abandons them to the police. Then he tries to dump Donnie in the same chemicals that made him what he is now.
- Blazing Inferno Hellfire Sauce: Joker spikes a bowl of chili at the local chili cook-off with "Five-Alarm Ha-Ha-Jalapeño," with rather horrifying results.
- Call-Back: One of Donnie's ideas for a crime is to encase people in giant playing cards, like in “Topsy Turvy”.Joker: Been there, done that.
- Conspicuously Public Assassination: Joker's plot to kill Mayor Grange at the Chili Cook-off cranks this as far as it can go. He spikes the chili with hotpeppers, then drives up in a purple firetruck (wearing a purple firefighting suit) and attempts to douse him with Joker Gas from the firehose."You should know better, Mayor. Chili always gives you gas!"
- Crazy-Prepared: Barbara borrows police equipment to compensate for lacking an arsenal on par with Batman.
- Deducing the Secret Identity: Batgirl is able figure out that Donnie is Prank by his Annoying Laugh.
- Everyone Has Standards:
- Barbara is the only one at Gotham High who isn’t laughing when she sees her and Donnie’s teacher tied to a flagpole.
- Donnie refuses to launch Batgirl because the impact would kill her, and he doesn't want to hurt people. He just wants to make people laugh.
- Faux Affably Evil: Joker genuinely acts like he just wants Donnie to be his pal. It isn't long before he's trying to dump him into a vat of chemicals simply because Donnie didn't want to harm people.
- Foil: Highlighted. Batman is a jerk to Batgirl and is reluctant to have a sidekick, but only because he's genuinely concerned about her safety. Joker is extremely nice to Donnie and actively sought him out as a sidekick, but only for petty, selfish reasons (he was jealous that Batman had a sidekick and he didn't) and attempts to throw Donnie into a vat of chemicals when he steps a toe out of line.
- Hollywood Acid: The acid Joker tries to dump Donnie in glows green.
- Kid Sidekick: The focus of the episode.
- Lame Pun Reaction:
- Donnie's joke about how "X=PU" doesn't get many laughs.
- Joker dubbed his assassination attempt on the mayor "Revenge is a dish best-served chili." Even Donnie isn't impressed.
- Ludicrous Gibs: Joker's plan to end Batgirl is by chaining her to a gumball and shooting it so she goes splat with it; this is what gets Donnie to second-guess teaming up with him.
- Mythology Gag:
- Joker's responses to Donnie's ideas are a shoutout to the Batman: The Animated Series episode "Mad Love".
- It's not the first time the Clown Prince of Crime has used a fire truck as part of his scheme, either.
- "Not So Different" Remark: Joker claims that he and Donnie are misunderstood comedians who are unjustly punished for harmless pranks.
- Not What I Signed Up For: Donnie is horrified when Joker ties Batgirl to a giant gumball and orders "Prank" to launch her. The way she's tied, every bone in her body would snap. Donnie refuses because he only wants to make people laugh.
- Series Continuity Error: This episode may have aired
Out of Order with the previous one seeing as Batgirl continues to complain about Batman not treating her as a partner, not to mention she still has her original utility belt and has to rely on outside resources in place of Batman's gadgets. - Would Hurt a Child: Donnie and Barbara are both high school students. This doesn't stop Joker from trying to murder Barbara and dump Donnie into a vat of chemicals to drive him crazy.
