Rocket was originally an ordinary raccoon, but was abducted and experimented on by the High Evolutionary, who enhanced him with cybernetics and genetic modifications. These experiments resulted in enhanced strength, durability, agility, and acute senses. He also gained a genius-level intellect, becoming a skilled engineer and weaponsmith. He dislikes being called a raccoon and prefers to be referred to as Rocket, likely due to the trauma of his experimentation. He escaped the High Evolutionary and became a mercenary, eventually joining the Guardians of the Galaxy. He was summoned to Reality Zero to fight against Galactus