Macchina magnifica

The Macchina Magnifica was a doomsday machine designed and owned by Leonardo da Vinci, and constructed with help from Philip J. Fry who was led to believe it was an ice cream machine. The machine was used to attack those on Planet Vinci who had made Leonardo and Professor Hubert J. Farnsworth feel inferior, but it was stopped and presumably ruined by Fry before it killed too many.

Trivia

 * Though its primary purpose is to exterminate everyone who ever made its inventor feel inferior, its byproduct is ice cream.