The Koopa Troopas are turtle-like creatures originating from the Mario games. They first appeared in the very first Super Mario Bros. game, and have appeared many more times after their debut. They are common enemies.
There are two main types of Koopa; Red Koopa and Green Koopa. There are also two main varieties of Koopa; the Koopa Troopas and the Parakoopas. The Red Koopa Troopa just walk along, but when they come to an edge they turn around and go back. Green Koopas on the other hand keep walking other the ledge, even to their death. The Parakoopa, which have wings and can fly. The red ones fly back and forth or up and down when the green ones bounce along the ground. When they are jumped on they loose their features and become a regular Koopa.
If a Koopa is jumped on then it will retract into it's shell. If it is hit again then it will shoot off at a high speed, which is dangerous to the character. In Super Mario World 2: Yoshi's Island; if a Koopa is jumped on then it will be forced out of it's shell. Koopas without shells wear boxing shorts. If it gets back to it's shell then it will enter it again. When Yoshi swallows a Koopa, he cannot turn it into an egg and he can only have it in his mouth to spit out. However if a Koopa has been forced out of it's shell than it can be swallowed and made into an egg.
In the Mario Sports games Koopa is usually Yoshi's partner and friend. But this Koopa is probably another legion of Koopa that isn't in Bowser's command.
Koopa Troopas and Parakoopas are references to army soldiers (troopers and para troopers). Some Koopas have spikes on their backs so they can't be jumped on (though this type is never encountered by Yoshi). Other enemies are also turtles, such as Lakitu.
The King of the Koopas is Bowser. Other notable Koopa are the seven Koopalings, Bowser Jr. and Hookbill the Koopa. Koopa Troopas also appear in Super Princess Peach in two forms and states. Normal ones walk normally while happy-singing ones jump after a walk.
Enemies Visit Koopa and Para-Koopa
Baron von Zeppelins