Planet Fusion is an enormous planet ruled by Lord Fuse that has been traveling through space for ages, breaking down planets and absorbing them. Now it has its sights set on our world, Earth, specifically the Cartoon Network Universe. The planet of Anur Phaetos, Ghostfreak’s home-planet, is assisting Planet Fusion. It has seemed to suck up some populated planets, turning the inhabitants into bloodthirsty fusion creatures. Of course, Planet Fusion appears in the background. According to the Halloween event, Fuse is behind the moon. But, apparently, areas in space such as the KND's moon base, the moon itself, and Lumpy Space would have received similar attention as Earth and attacked. The Glorft managed to repel a Fusion invasion, and Ghostfreak's home planet of Anur Phaetos joined Fuse's forces to prevent an attack.
- At practically anytime (except at the Academy), the player can scroll the mouse to the sky where planet Fusion can be seen.
- Although it is officially called Planet Fusion, some sources now say Planet Fuse.