In the Treehouse of Horror segment Time and Punishment, Homer tries to repair a broken toaster and accidentally invents a time machine.
Homer proceeds to make mistakes which change elements of the future in many ways. Like creating a world where it rains donuts.
One alternate universe was to feature an additional Simpson family member named Roy who would surprise Homer as a teenaged son he never knew he had. The scene was cut from the episode, but the writers never forgot Roy. When a clueless Fox executive recommended that the show introduce a new family member to spice things up, they brought Roy out of exile to become a snarky parody of Fox's ridiculous request. Roy is introduced in The Itchy & Scratchy & Poochie Show which was meant to mock shows randomly introducing characters to boost ratings.