Leonardo Da Vinci is a character from the Futurama episode "The Duh-Vinci Code". He is obviously based off the real-world Renaissance artist of the same name.
He was voiced by Maurice LaMarche who also voiced Alec Baldwin's Team America: World Police counterpart.
It is revealed in the episode that Da Vinci travelled to earth milleniums ago, where he was considered a genius for his many inventions. He soon returned for his home planet for being surrounded by people much less intelligent than him.
Thanks to one of his hidden inventions, Fry and Professor Farnsworth are sent to his planet and meet him in person. Da Vinci reveals to Fry that - despite his intelligence - he is the dumbest inhabitant on his planet, and he is constantly ridiculed by the smarter inhabitants. Then he hires Fry to help him build a new invention called the Machina Magnifica.
Later, the other inhabitants arrive to witness Da Vinci's creation. However, Fry discovers it is a doomsday machine, which Da Vinci plots to use in destroying his enemies. Climbing into the machine, Fry shuts it down before it could kill anyone. Da Vinci tries to reactivate it by pulling a lever, only to be killed when a large cog crushes him.