After surviving an explosion in the city of Nightshade, Packrat and his gang take Spider-Man 2099 to their hideout in order to make him to activate the robot, which he does. Once activated Flipside becomes a combination of Venom and the original Spider-Man, since Spider-Man 2099 does not exist in his outdated records. Flipside then jumps into Spider-Man 2099's arms and says they will be best friends or he'll kill him. When Spider-Man 2099 rejects his friendship, Flipside becomes enraged and attacks Spider-Man 2099. Flipside has battled Spider-Man 2099 many times but never defeated him and after yet another defeat Flipside ran away and has not been seen since.
Flipside appeared in the Spider-Man video game "Spider-Man: Shattered Dimensions" as an alternate costume and mentioned in a joke saying " Whoa this guy makes Flipside seem sane."
Flipside also appears as an alternate costume in "Spider-Man: Edge of Time".