Green Koopa

An enemy from the original [https://en.wikipedia.org/wiki/Super_Mario_Bros. Super Mario Bros.] The Koopa, also known as the Koopa Troopa, is often alongside Goombas, and is one of many enemies that try to stop Mario from rescuing Princess Peach from Bowser, or King Koopa. There are many types of Koopa, including the green and red Koopas in [https://en.wikipedia.org/wiki/Super_Mario_Bros. SMB], and the blue and yellow Koopas in SMW, and appears in nearly every mainline game. The Koopa can be defeated by stomping on it to knock it out of it's shell, then stomping on it again. The shell can be kicked to break or activate certain blocks.

Some variants of the Koopa include the Paratroopa and Dry Bones.