Tom is a man from Springfield who temporarily became Bart's "Bigger brother" after Bart and Homer had a falling out, Bart decided to try getting a new dad through the Bigger Brother program and was hooked up with Tom. Tom is a Navy pilot who owns a motorcycle and treated Bart extremely well.
Eventually, Homer found out and gets his own "son" through the program named Pepi. Homer and Tom eventually met and got into a huge fight. In the end, Homer was injured and Tom became Pepi's new Bigger Brother.
Tom has similar traits to Homer, wearing the same clothes and even saying "D'oh" in frustration. He is generally the opposite of Homer, being fit and healthy with a full head of hair.
Behind the Laughter
Originally he was to be voiced by Tom Cruise, but they could not get him to perform. Phil Hartman was called in to do it.