Shell

Koopa Shell (also known as Turtle Shell or Shell) is a murder weapon seen being burped out of Baby Animal's mouth. It made Mario shrink into his mini form. When Mario exclaimed, "You tell me where the princess is, or else!", Baby Animal replies to him, "Or else what? Shell?" After Mario asked what he said, Baby Animal told him "Shell" again, and Baby Animal burped the shell out of his mouth. When the shell came in contact with Mario, it caused him to shrink into his mini form, which opened a chance for more puns. It appeared in Super Mario.

Biography
It only appeared in The Magic Lamp]].

It is a popular weapon in the Mario series as it is the shell of a Koopa (an anthromorphic turtle that is a popular enemy of Super Mario) that can be kicked to kill other enimies (and hurt Mario).

Trivia

 * Shell is the same green Koopa Troopa shell used in the Mario series.
 * Apparently, there is a wall behind Mario when he first met Orange. It should have hit back (as it did in all the Mario 2-D Platformers) and killed him rather than Bullet Bill. The reason why it failed to rebound is unknown.
 * The sprites for the Koopa Shell, Bullet Bill, and Super Mario, are all derived from the 1990 Super Nintendo Entertainment System (SNES) game, Super Mario World.