Ah, the Goomba, a classic enemy. The Goomba has made various appearances, which its first was in 1985 on Super Mario Bros., in many of the Mario games over the years. The always squishable enemy has been stomped, smacked with hammers, and flamed by fireballs over the years by Mario and Luigi. The Goomba's role in Mushroom Kingdom Fusion is the same as it's always been in past games. All one has to do is stomp on it or have a shell thrown at it and there are no more worries.
Goombas are unique amongst the other enemies in that their apperance sometimes changes to match that of their surroundings. For example, they wear clown makeup to fit in at Toyland and dress in a style called Rhinstone Goombas in Fever Las Vegas. These changes are purely cosmetic and have no effect on the Goomba's abilities.