The episode had a scene with a laughing fish (as a result of Joker's gas being dumped into Gotham Bay), which got cut for time reasons.
Metropolis, the city Detective Yin is from, is the city Superman (another famous DC hero) lives and works under his alias Clark Kent.
So, Yin and Bennett jump into the moat around Arkham and expect it to have NO security features?
Joker: (after Batman foils his plan) You made me a very sad clown! (sees Batman isn't on the balloon) Hey, where'd you go?
Batman: Knock knock.
Joker: Who's there?
Joker: I was feeling a little screw-loose, so I let myself in.
Batman: Stop this thing, Joker!
Joker: With what brake?
Joker: (while fighting Batman) You know, I really love this place. My hide-out's a shambles. And these digs just scream me! (tired of fighting) Ok, take back the asylum, but mark my words: This town has happy days ahead!
Batman: Who are you?
Batman: Not what, who. (Tries to smear off Joker's make-up, but it won't come off)
Joker: Smear free. It's perma-clown. (Sees that Batman isn't laughing) Oh, tough crowd.
Ethan: Last night ... I saw the Batman.
(Alfred drops a vase in surprise)
Alfred: Not to worry. Only a Ming.
Joker: If you like me now, wait 'til you get a load of my POP!
Bruce: I know, Alfred. Time for swinging bachelor Bruce Wayne to put on the party hat.
Alfred: Rest assured, master Bruce, you're never far from the batcave with a modern miracle of batwave.
Joker: Stop me if you've heard this one before, Batman. There were these two fellows in an abandoned party favor factory. One says to the other --
Batman: Where are you keeping the gas, Joker?
Joker: You call that a punch line?
Batman: I don't share your sense of humor.
Joker: My precious gas ... passed by a party pooper.
Batman: I had a different punch line in mind.
Joker: They all said I was sick in the head. They said I needed help. Well, maybe I am a bit batty. Blame it on the bats in my belfry.
Alfred: It's an anniversary, Master Bruce. Three years ago tonight, you first donned cape and cowl.
Bruce: Crime flies.
Alfred: Chop-chop. Make a wish.
Bruce: I wish ... I wish ...
Alfred: I know. I wish they were here, too. Very much so.
Bruce: To the memory of Thomas and Martha Wayne ... the reason I became the Batman.
Batman: Listen, Joker, you're sick. You need help.
Joker: Well, maybe I am a little off. But what are you gonna do? Lock me in the loony bin? I'm already here!
Thorne: How -- how'd you do that?
Batman: I'm the Batman.
Metropolis, the city Superman protects, is mentioned in this episode.
Kevin Michael Richardson, the voice of The Joker, also plays Carlton Duquesne, in the animated movie "Mystery of the Batwoman".
This episode along with "Traction" and "Call Of The Cobblepot" was released on DVD as The Batman: Training For Power.
Chief Rojas mentions that Detective Yin is from Metropolis.
This incarnation of Joker slightly differs from his previous animated incarnations in terms of his facial appearance. This Joker has eyes with yellow pupils and blood-crimson irises/whites and his teeth, though yellowed like his animated predecessors, are misshapen and uneven. In this episode, they have a squared, jigsaw-like pattern, enabling him to still perform the trademark Joker Smile with no difficulties. In all subsequent episodes, his teeth are simply misshapen and crooked. In fact, they seem to appear differently in every episode.
Actor Rino Ramano is no stranger to voicing superheroes, as he played Spider-Man in the 1999 series, Spider-Man Unlimited.
It's revealed that Bruce Wayne's birthday is in October.
UK airdate: July 11, 2005.
This version of Batman has shorter ears and claws as part of his gloves.
Cartoon Network airdate: April 2, 2005.
Detective Ellen Yin in this series looks like, dresses like, and has the same job as detective Elisa Maza from the series Gargoyles.
Bruce Timm, Eric Radomski, and Paul Dini are all given a nod as they are caricatures on the faces of escapees from Arkham.
Bat vehicle debuts: Batmobile, Batboat.
Bat-gadget debuts: Batarang, grappling hook.
In most incarnations of the Joker's laughing gas, it is lethal. However, since this is a kid's series, the gas only puts its victims in a catatonic state.
In this series, the Joker is depicted in no way that he's been depicted before. He is dressed in a jester/straightjacket costume, has dreadlocks, and fights somewhat like Toad from X-Men.
The character Ellen Yin may be a nod to Ellen Yindel from the graphic novel "The Dark Knight Returns," where in a possible future she replaces Jim Gordon as commissioner and starts hunting Batman.
The bats flying at the screen every time a scene ended is also a nod to the Batman (1966) series.
The Monarch theater, from the original movie, is shown for the first time.
The Joker is introduced.
In the 1989 movie, the Joker held a small parade with gas-filled balloons that he was going to use on the populace, very similar to how the Joker was going to do it in this episode without the fanfare.
The main title design and the poles in the Batcave are nods to Batman (1966) that starred Adam West, who voices the mayor in this series.
Ratings: 3.7/15. The average for this week was 3.3/16.
This is the first animated Joker since the old cartoons before the 90's that isn't voiced by Mark Hamill.
The guard checking all the cells in Arkham said two names, "Steiner" and "McSwain." A nod to one of the producers and to one of the casting directors for the show.
Batman: Gotta work on those stops.
In the 1989 Batman movie, Batman remotely calls the Batmobile as he does in this episode, while on the run with Vicki Vale from the Joker. He steps out into the middle of the street as the Batmobile barrels down on him, stopping just inches away from his legs.