Hugo Simpson II

"I made a Pigeon-rat!"

- Hugo when he shows Bart a creation of his. "So I have two brothers?"

- Lisa saying that Hugo is one of her brothers besides Bart.

When he was born he was a conjoint twin and later he was separated from his twin brother Bart a short time after birth; also he somehow tried to eat or bite Bart's arm like it was food. His parents and Dr. Hibbert found out that his scar was on the wrong side and Hugo became a good guy once again, leading to him and Bart switching places.

Triva

 * The reason he turned to the dark side, because Dr. Hibbert was the one who separated him from Bart.
 * He is voiced by Nancy Cartwright.
 * In The Simpsons Hit and Run game he appears as a costume for Bart.