Johnny Skydiver is a professional skydiver who appears in the Season 5 episode Rigby in the Sky with Burrito, to help Rigby skydive into his high school reunion.
Muscle Man says he can bring them to a friend of his the next day after having relations with Starla (which prompts them to try and tune him out), Johnny Skydiver, who owns a plane and a favor to him. The next day, they meet Johnny who says he is flying a banner over the reunion anyways. However, he first must fix his plane which is in dire condition. 20 minutes before the reunion, Johnny says the plane is fixed and gives Rigby a crash course in the basics of Skydiving.
Looking at the still decrepit state of the plane, Mordecai tries to talk him out of it but Rigby said that he has to, and admits it was Mordecai who was the cool one in high school. Mordecai tries to tell him that no one will know if Rigby lies but Rigby then climbs aboard and claims that he'll know and that is why he must do this.