Brain Slug

Brain Slugs are little parasitic slugs that attach themselves to the heads of intelligent beings (such as humans) and control them. They are about as big as a fist, green, translucent and have two feelers and one enormous eye.

Symptoms of Posession
A person posessed by a brain slug will be likely to speak in a monotone voice and do everything to further the spreading of brain slugs throughout the universe, but the easiest way to tell a person is infected is by the brain slug sitting on their head. The recommended procedure of dealing with a brain slug victim is to act natural and switch to a garlic shampoo. Another way to deny attachment is wearing a helmet. Fortunately, brain slugs are not very intelligent, minimizing the risk. Once removed from the afflicted person's head, the person returns immediately to normal.