Koopa Troopas are turtle-like enemies that will hide in your shells if you jump on them. A variation of these is the Koopa Paratroopa.
- They have red and green shells. Red shelled ones will turn around when they come to an edge and green ones will just fall off.
- There is a Koopa Troopa with a blue shell in the Mario vs. Luigi mode. Jumping on this results in it hiding in its shell, which you can touch and you will turn into Shell Mario/Luigi.