Leon Kompowsky

Leon Kompowsky, a "big white guy who thinks he's the little black guy", is a mental patient who thinks he's Michael Jackson.

Voice Actor
He was, in fact, voiced by Jackson (who, for contractual reasons, was credited as "John Jay Smith") and his singing was done by Jackson impersonator Kipp Lennon.

Role in The Simpsons
In "Stark Raving Dad", Homer gets hospitalized for wearing a pink shirt to work, and while in the hospital, meets a patient who calls himself Michael Jackson and thinks that he is the famous singer, although he's a middle-aged caucasian man. After getting released, Homer invites him to come visit his home (Kompowsky was in the hospital voluntarily) and Bart, thinking Kompowsky is the real Michael Jackson, tells everyone. The entire town shows up to see Michael Jackson, only to learn it's fake. Bart becomes hated in the town, and Lisa hates him too for forgetting her birthday. Kompowsky decides to set things right and helps Bart write a special birthday song for Lisa. In the end, his work is done, so Kompowsky drops the Jackson charade and starts talking in his normal voice (voiced by Hank Azaria) citing his reasons for doing the voice was a result of anger and he felt respected when he did the Jackson impersonation, he then cites his work at the Simpson home was done prior to leaving.

Other Plans
Kompowsky was set to later return, except this time as Prince, but the idea fell through.

Other Appearances
Kompowsky does make an appearance in the Simpson comic, as a janitor for the mental facility. He has not made an appearance since.

In 'The Simpsons 2009 Calender', he can be seen as part of the angry mob for the month of February.

In a Bongo cartoon(Spain version),he makes a appearance,although it is not known this is Leon