Other mistake: When Alfred serves Bruce coffee at the end, there's no steam coming from the coffee pot or Bruce's mug when Alfred pours the coffee into mug.
Other mistake: Croc's feet are briefly a shade of pink after his sewer fight with Bane.
Batman: The Animated Series (1992)
2 other mistakes in season 3
Starring: Mark Hamill, Kevin Conroy, Efrem Zimbalist Jr., Loren Lester, Bob Hastings
Genres: Action, Animated, Crime, Drama, Family, Fantasy, Mystery
Factual error: Batman is in Japan and tracks down Kyodai Ken by using Caller ID, which returns a seven-digit "555" number. Telephone numbers in Japan have 8 digits.
Christmas With the Joker - S1-E38
Joker: Jingle bells, Batman smells. Robin laid an egg. The Batmobile lost a wheel and the Joker got awaaaaaaaaayyyyy.
More trivia for Batman: The Animated SeriesMore questions & answers from Batman: The Animated Series
Answer: Because he stole a chemical from his lab.
But Batman knew that with it, Clayface could permanently retain his shape and Clayface desperately wanted to be Matt Hagen again. In a sense, Batman stopped Clayface from becoming human.