Mega Goombas are gigantic versions of Goomba that are bigger than Grand Goombas. In fact, they are the biggest species of Goombas.
 New Super Mario Bros. Wii
Mario fighting two Mega Goombas
in New Super Mario Bros. Wii
Mega Goombas first appear in New Super Mario Bros. Wii. Mega Goombas only appear in the World 1 Enemy Course where two of them appear trying to stop the player from saving the kidnapped Toad. Mega Goombas attack the same way regular Goombas do by simply walking into the player. When jumped on, they split into two Grand Goombas. If ground pounded, it splits into four Goombas. It takes four Fireballs to defeat a Mega Goomba. Mega Goombas can't be frozen by iceballs from Ice Mario; they will break out instantly after being frozen.
 New Super Mario Bros. U
Mega Goombas reappear in New Super Mario Bros. U. They act the same like in New Super Mario Bros. Wii, when they are jumped on they split into 2 Grand Goombas. They are found in Soda Jungle's course Jungle of the Giants with Gargantua Koopa Troopas. They can be defeated by Koopa Shells now. Additionally, they appear in a challenge called Big Goomba Bounce Bash.