The Piranha Creeper is a special type of Piranha Plant that acts a lot different than them. They are attached to vines and make residence in pits or holes in the wall, with the Creepers moving on a set pattern in and out of their entry point. Since the vine has thorns on it, you cannot come into contact with it at all, since you will take damage. In order to defeat Piranha Creepers, you have to attack the head (takes damage from most attacks). This will cause it to retreat some and stop moving, but you need to keep doing this until you get to the “root,” where hitting it one more time will get rid of it for good.