Koopa Troopas (Or Koopa) are turtle-like enemies in the Mario series. They tend to have multiple colored shells, most popular being Green and Red. Green Koopas have the ability to walk anywhere they want. Red Koopas are careful and tricky. If they walk to a ledge, they will turn back and walk again. When Red Koopas are swallowed by Yoshi, Yoshi can keep it in his mouth for as long as possible. If he spits it out, he will breathe fire, causing a dramatic amount of damage. Koopa Troopas are minions of Bowser and in Super Mario 64, they can be knocked out of their shells and the shells can be used to surf on lava, water, freezing water, land, and more. One infamous koopa in Super Mario 64 is known as Koopa The Quick. Their 4D counterpart is the Roopa.