Mega Goomba (boss)

The Mega Goomba is the boss of World 4 in New Super Mario Bros.

Before the battle, a seemingly regular Goomba walks onscreen before transforming into the Mega Goomba and commencing the battle. When it grows, it makes a sound similar to touching a Mega Mushroom, only somewhat more menacing. Mario (or Luigi) must defeat this boss to acquire the key that provides access to World 5.

To defeat the Mega Goomba, Mario can activate a switch, causing two platforms to appear. When Mario stands on one of them, it will elevate in the air. From there, Mario can either wall-jump, jump, or ground-pound directly on top of the Mega Goomba. For the attack to be successful, Mario must ground-pound the Goomba (unless he is Mega Mario or Shell Mario). Mario can also go off to the side, simply wall-jump, then ground-pound on the Mega Goomba. It is possible to defeat the Mega Goomba without using the ? Switch. To do this, Mario must perform Wall Jumps. If Mario is in his Fire form, he can also defeat the Mega Goomba if he stays on the far left area and shoots enough fireballs to defeat it; when the Mega Goomba approaches Mario on the far left side, it does not hurt him due to its mushroom-sized hitbox.

Once Mario ground-pounds the Mega Goomba three times (or nine times if Mario is in his Mini form), the Goomba will be defeated, and Mario can get the key to World 5.

Trivia

 * In the very first footage of New Super Mario Bros., the Mega Goomba was a normal Goomba until it came into contact with a mushroom.
 * It is the only boss in New Super Mario Bros. that shrinks when defeated.