Future Rigby has longer and shaggier hair than his present self, and it appears to be combed over a little. He also has a bushy light brown mustache and the fur on his tail is shaggy. He wears a chest plate with Park Rangers insignia with a green jacket (also with insignia on the shoulder), black fingerless gloves, green pants with a black belt and grey knee pads, and black boots.
He tries to stop Mr. Ross from destroying the universe, which was caused by Mordecai and Rigby trying to build Ross' time machine. When the rest of his team is incapacitated by Ross, and after Rigby learns the whole ordeal was due to something he did to Mordecai in the past, Rigby takes his ship and tries to go back in time to fix his mistake. However, Future Mordecai, who turned evil and now works for Ross due to what Rigby did to him, follows him, and when he catches up with him he threatens to shoot him. Rigby, who also pulls out his gun, presses the button, and the two shoot and hit each other. Future Rigby arrives in the present and crashes in the park. The Park crew gathers around the ship, and Future Rigby staggers out of the ship, badly injured from his wounds from getting shot. He tells them about Mr. Ross and how he and Mordecai tried to finish his time machine in high school. It exploded, created a "Timenado" that is slowly destroying the universe, and got the two expelled from high school. He also reveals that Mordecai shot him, and he tells his present self to not make the same mistake he did. He then dies, and present Rigby puts his body on the front steps of the house, and puts his hand into a thumbs up. After Future Mordecai dies, his body is put next to Future Rigby's, and they both disappear after their present say they won't shoot each other, which erases the timeline in which that event would happen.
- Not to be confused with the Future Rigby from Mordecai and the Rigbys.