The character is portrayed by Christopher Lloyd in all three films, as well as in the live action sequences of the animated series. He is voiced by Dan Castellaneta in the animated series. The character's appearance and mannerisms are loosely inspired by Leopold Stokowski and Albert Einstein. He is of a benevolent mad scientist archetype, with his madness being visionary and eccentric enthusiasm rather than insanity or evil. He is the only character to appear in all Back to the Future media.