Adolf Hitler

Adolf Hitler was an Earthican dictator who served as Chancellor of Germany.

Adolf Hitler in Futurama
His brain was once put in the body of a great white shark by Professor Farnsworth in favour of scientific advances. He is often referenced in popular culture, as well as in common dialogue as a symbol of prejudice. Bender called Fry an Adolf, the steering wheel from Hitler's staff car was used to help build Project Satan , and Hitler was played by an unknown Human actor in the second episode of The Scary Door, a popular TV show in the 31st century.

When the Planet Express crew went to the second universe with a forward time machine, the Professor stopped in the 20th century to shoot Hitler, and was successful. In the third universe, however, Farnsworth didn't manage to kill him, as he hit Eleanor Roosevelt by mistake. (See an explanation of this with a picture.)

Trivia

 * He was born exactly 110 years before "Fear of a Bot Planet" first aired on Fox Network. This episode dealt with extremely racist Robots.
 * The most common way of keeping Human heads alive is the technology of head jars. For reasons unknown, the scientists at Mars University chose to save Hitler's brain in a very unusual way. (It's possible they didn't actually keep him alive, as he proved himself to be a dangerous person back in the 20th century.)