Hugo Simpson (non-canon)

Hugo Simpson (II) is Bart's conjoined twin brother in the 7th Treehouse of Horror. Not long after their birth they were separated by Dr. Hibbert. Bart, Lisa and Maggie found Hugo living in the attic after Homer told the kids about the other Simpson child. Because Homer and Marge thought he was the evil twin, they locked him up in the attic and every week was given a bucket of fish heads to eat. Hugo did experimental surgery for his upcoming reattachment to Bart, and accidentaly created a Pigeon-Rat in the process. The Simpsons later found out that Bart was the evil twin so Bart took Hugo's place but came back after the scene with Hugo sitting at the dinner table.