Batman: The Animated Series: 10 Best Characters Who Only Appeared In One Episode
4. Sidney Debris - The Man Who Killed Batman
Sidney Debris, otherwise known as 'Sid the Squid' was one of the most hilarious characters in the entire series. A sympathetic yet clumsy criminal, Sid dreams of being a big shot in the criminal underworld. Sidney's wish happens to comes true, for better or worse, as his clumsiness leads to the apparent demise of Batman.
The Gotham underworld celebrates Sidney's victory, giving him the title 'Sid the Squid.' However, due to his newfound fame he also makes a few enemies. These enemies include the Joker and Rupert Thorne, who believe Sidney to be some big crime lord.
Joker despises Sidney for "killing" Batman, leading to the Clown Prince of Crime attempting to kill Sid by locking him in a coffin and pushing him into a vat of acid. The bumbling fella manages to survive the ordeal and heads to Thorne for help, with the crime boss believing Sidney was after his territory.
As it turns out, Batman obviously is not dead, and Sidney discovers that being the man who killed Batman is not all it is cracked up to be. And while the Dark Knight does turn Sidney over to the authorities, he gets a happy ending as the rest of the criminals believe he is a big shot after the events of the episode.