Evil Troy is an alternate version of Troy Barnes, the product of a divergent timeline in which the study group suffered great personal losses. Troy himself severely damaged his throat and had to have surgery to implant a voice box for him to be able to talk. Devastated by those tragedies, that reality's Abed dubbed this The Darkest Timeline, and suggested they become as dark and twisted as the reality they had to endure. Evil Troy was the only one to initially join him in his plans although later Evil Jeff and Evil Annie come around. They all now plot to destroy the "Prime Timeline". His first appearance was in the Season Three episode "Remedial Chaos Theory". He is portrayed by Donald Glover.
In the study group's third year at Greendale, Troy and Abed decided to move in to an apartment together. A housewarming party was thrown where a the roll of a Yahtzee die determined who would go downstairs to grab the pizza from the delivery guy. Out of the six different scenarios, it's the one where Troy gets the pizza that creates The Darkest Timeline. He slams the door on his way out, causing the boulder from the Indiana Jones diorama to roll on to the floor and starting the fateful chain of events. The culminated in Pierce bleeding from a gunshot wound, and a fire that broke out with the Norwegian troll doll in the center of the chaos greeting Troy when he returned. Troy was in hysterics and believed the troll doll was responsible for what happened. In hopes of destroying it, he swallowed it while it was on fire.
Troy reacts to the chaos.
This resulted in him injuring his throat and having to have an electric voice box installed to speak. In the aftermath of the event, Pierce died from his wound, Annie was institutionalized from the guilt, Jeff lost an arm due to the fire, and Shirley became an alcoholic. Afterwards, in that reality's study room, the remaining study group members have a meeting. The Abed of that timeline had a plan; they would all commit to becoming "evil" by wearing felt goatees, cross over to the "Prime Timeline" and take over their counterparts lives. They others are too traumatized by their fates and leave annoyed by Abed's proposal. Only Troy stays behind and dons the felt goatee. The two do their signature handshake and proclaim "Evil Troy and Evil Abed!". ("Remedial Chaos Theory").
Evil Abed's plot to invade the Prime Timeline failed and Evil Troy was put off by his new attitude. Evil Abed no longer wished harm upon the other reality and decided instead to focus his on improving the Darkest Timeline. Evil Troy was put off by his best friend's attitude and turned his back on him. He joined Evil Jeff's crusade to continue Evil Abed's original plan to darken the Prime Timeline. Evil Troy followed Evil Jeff and Evil Annie after they crossed over into the other reality. He was accompanied by Evil Britta and Evil Shirley and they were all decked out in team uniforms consisting of black leather. They were also equipped with special teleporting paintball weapons. The Evil Study Group found their friends in the Prime Timeline study room.
The rest of the Evil Study Group arrives.
The Evil Study Group searched the campus for their counterparts and wound up in the cafeteria. They were shocked by the return of their reality's Pierce who wanted to join them. Unexpectedly, both he and Evil Britta wound up shooting themselves and they were sent back to The Darkest Timeline. The other Study group made their presence known and once the battle began, Troy and Evil Troy bumped into each other going backwards. Evil Troy admitted he was out of paintballs so Troy shot him in his throatbox sending him back to the Darkest Timeline ("Advanced Introduction to Finality").