John Kassir is an actor and voice actor who has been involved in the making of such shows as Afro Samurai, Rocket Power, and Johnnytime. His most famous acting role is the Cryptkeeper from Tales from the Crypt and its animated spin-off, Tales from the Cryptkeeper. He also served as the replacement for Charlie Adler as Buster Bunny in Tiny Toon Adventures.
Kassir voiced the Ice King in the Adventure Time animated short. The role was taken over by Tom Kenny when the series was picked up by Cartoon Network.