Troy is a frequent background character.
In "Big Stan on Campus", Stan recognizes him at a Groff Community College student room party, but Troy ducks out rather than acknowledge Stan's greeting. He is also at the college graduation in "Pride Before the Fail".
He also appears at Fro-YO-MAMA in "Holy Shit, Jeff's Back!", plays basketball with Roger in "Criss-Cross Applesauce: The Ballad Of Billy Jesusworth" and appears at the reading of Steve's cheerleader article at Pearl Bailey High School in "Garfield and Friends".