Brent Forrester
Wikisimpsons - The Simpsons Wiki
Brent Forrester is a writer who used to write for The Simpsons. He has also written for The Ben Stiller Show, Mr. Show with Bob and David, King of the Hill, The Office and Undeclared.
Forrester also showed some voice talent by doing the voice of Leon the Drug Addict in the episode of King of the Hill "Junkie Business".