This article is for the creature from the Metroid series. For the animal, see Bull.
Bulls are green and spherical in appearance, and they have many tubes surrounding their bodies where they release gas from. Because their bodies are filled with gas, they are very lightweight and when shot with beam weapons the impact causes them to be pushed back a great distance. However, they have a tough exterior that can only be penetrated by a few weapons. They can be found in the Wrecked Ship and underneath the quicksand in Maridia.