From Wikipedia, the free encyclopedia. Jim Ross Meskimen (born September 10, 1959) is an American comedian and actor, perhaps best known for his work on the improvisation show Whose Line Is It Anyway? and as the voice of President George W. Bush and other politicians for the internet Jib Jab animated shorts. He voices Thom Cat, Neighbor John, and Stumpy in Random! Cartoons. Meskimen was born in Los Angeles, California, the son of actors Marion Ross and Freeman Meskimen. He is a Scientologist.