Galactus is the Devourer of Worlds. However, in Super Smash Bros. Crossover, he is currently a neutral character. Galactus was first seen at a meeting held by Master Hand to discuss the situation about Meta Knight. Galactus is later seen traveling the universe following the formation of the Smash Bros. Galaxy when he is hit by metal, which is being pulled toward the Smash Bros. Galaxy as Wiseman initiates his master plan.
Galactus later reappears after being summoned by the Silver Surfer to help out in the final fight against Mechtavius Destroyer.
During The Grand Finale, Galactus is seen talking to his alternate reality counterparts when the Zombie Galacti, consisting of Zombie Giant-Man, Zombie Spider-Man, Zombie Wasp, Zombie Luke Cage, and Zombie Hulk arrive, intent on eating the Galactus to curb their hunger. Initially believing that the Zombie Galacti would be no trouble, Galactus is quickly proven wrong when the five zombies devour the other Galactus with minimal effort. Aware that he would stand no chance against them, Galactus uses the feeding frenzy as an opprotunity to escape. Unfortunately, Mechtavius Destroyer shoots Slycerak at Galactus so he can't escape, and the Zombie Galacti proceed to devour Galactus.
- Galactus is the only giant character in Super Smash Bros. Crossover that doesn't have to change his size.
- Galactus, Way Big, Ultimate Way Big, Mechtavius Destroyer, Evil Way Big, Zorc Necrophades, Gigadark Bowser, and Rosalina (in her giant form) are the largest characters in Super Smash Bros. Crossover.