Thad Jarvis is an expert Guitar Hero player. In the episode "Guitar Queer-O", he is selected by a talent agency to score one million points in the Guitar Hero game with Stan Marsh. However, he quits when Stan gets addicted to Heroin Hero and becomes a crabby jerk and when Stan wanted to play "Cheap Trick", Thad calls it 'bubblegum crap'.
Thad wears a black shirt and blue jeans. He has curly brown hair which falls over his right eye. His mouth appears high up on his face and is usually hanging open slightly. One of Thad's distinguishing features is that he appears to be always looking up.