Answer: Tim Curry
During the cast of the 1
Curry was the original voice from The Joker in Batman: The Animated Series but after Curry recorded the first episodes and tested them on the screen with the audience, Curry was cut out of the cast. The reason? His portrayal of The Joker was extremely unsettling for the children in the audience. His pronounced voice and intensity were perhaps a little too much even for the exaggerated wild character.
Batman: The animated series may have been dark, gritty and convincing for an animated series for children But at the end of the day it was still a show for children and it was bad for business, the target audience right in front to scare the door. Curry was replaced by Mark Hamill, who spoke The Joker for the rest of the series and in several Batman animated films and video games.