They are turtle-like creatures who hide in their shells when someone stomps on its head. The Koopa Troopa is the most common classification of Koopa. Koopa Troopas are often troopers in the Koopa Troop. Koopa Troopas come in four colors: Green, Red, Blue, and Gold. If an enemy is referred to as just "Koopa" this usually means Koopa Troopa, the green koopa troopas are known to walk of cliffs and can't jump.