Inspired by just having watched the "Killing Joke" animated movie in the theater (which I enjoyed).
I recently rewatched the episode "Deep Freeze", in which a wealthy theme-park owner kidnaps Mr. Freeze, takes him to his futuristic theme-park/ city of tomorrow, and wants Freeze to build him a cryogenic suit like his to live forever. The episode is 20 years old and I just realized today it's an homage to Walt Disney, Epcot and the frozen head rumors. Man, I love that show.
Cesar Romero refused to shave his mustache, so they just painted over it on the show. That's amazing.