Trevor is a minor character who appeared in "The Line Substitution Solution". He is portrayed by comedian Blake Anderson.
He meets up with his friends in the Avengers movie screening line, right in front of the guys. Despite the fact that Leonard, Raj, and Howard have no problem with this, Sheldon does, and he proceeds to confront Trevor for his actions. Trevor points out that his friends saved him a spot in line and that it's cool, but Sheldon protests to this, telling him to go to the back of the line. Trevor appears to be sympathetic towards Leonard, knowing how frustrating Sheldon can be.
Later, he seems to be able to have a rebuttal for every argument Sheldon throws at him, such as the Avengers being rule breakers to accomplish their missions, and for working for a sanctioned department of the California government (the DMV-Department of Motor Vehicles) just like them. Sheldon even goes so far as to announce his line cutting to everyone, using Rosa Parks's civil rights action to bring a sense of guilt. However, this only leads to him being called out for having Stuart hold his line spot for money, and Trevor is let into the theater for the screening regardless of Sheldon's refusals.
Although his name was never said in the episode, it's shown in the closing credits.