Koopa Troopas (also known as simply Koopas) are enemies in the Mario series, they also appear as characters in the Mario Baseball series. Green Koopa Troopas have average stats with slightly average pitching, and the Red Koopa Troopa will use some of it's speed to improve batting skills. 

In  Mario Super Sluggers, they have high batting and running skills with low pitching and fielding skills. 
Koopa troopa