Repto Slicer is a blue lizard-like being that was originally created by Bling-Bling Boy. He first appeared in The Return of Johnny X. Bling-Bling wanted a pet for himself, but didn't want a dog, he wanted something unique. And thus, Repto Slicer was born. However, Bling-Bling was a terrible owner to Repto Slicer, as he kept him in a dark closet and barely fed him. Because of this, Repto Slicer went on a rampage and attacked the town. Later, Johnny Test tames him and keeps him as a pet. In the episode Johnny and Dark Vegan's Battle Brawl Mania, Dark Vegan says that Repto Slicer looks like a creature from the Planet Razorium. For that, Repto Slicer is sent to Razorium where he is happy.