Bombshell Koopa

Bombshell Koopas (originally known and known in Japan as Nokobon) are a black-shelled species of Koopa Troopas found in the game Super Mario Land. Bombshell Koopas are immune to Superballs, but they explode shortly after being stomped (although the blast radius is not very large), making them similar to Bob-ombs. They replaced conventional Koopa Troopas in Super Mario Land because it would have taken too long to program the ricochet effects of Koopa shells on the Game Boy.

Bombshell Koopas are the most common enemy in the Super Mario Land, appearing in all levels except for 2-3 (the underwater level), and 4-3 (the flying level). Like red-shelled Koopa Troopas, Bombshell Koopas do not walk off edges, but merely pace back and forth on the platform.

In Super Mario Land 2: 6 Golden Coins, normal Koopa Troopas appear as enemies, and while a new beetle-like enemy fills the exploding-shell niche, their name, Noko Bombette, is a reference to their "Nokobon" predecessor. (Bombshell Koopas were only referred to as such in the 2011 port of Super Mario Land to the Virtual Console, almost twenty years after Super Mario Land 2: 6 Golden Coins was released.)

Trivia

 * The exploding Black Shells from Mario Kart Arcade GP are possibly Bombshell Koopa shells.