About 1.5 milliliters of indestructible toxic slime standing anywhere from .5 millimeters to about .5 centimeters, Goobie (as the superhero community has taken to calling him) somehow gained sentience and quickly adapted a complete understanding of the English language. Most people just chalk it up to some crazy chemistry experiment gone wrong, but regardless of his exact origin, Goobie is capable of irradiating (and thus killing) anybody he touches simply by seeping through their skin. His molecular structure is such that he can appear as a semi-solid contiguous mass (pictured), or disperse into millions of tiny particles. In this form, he can act as an airborne virus, letting the wind carry him around, infecting as many as a hundred people at a time. This infection can lead to death in as little as a second or as long as a month, depending on Goobie’s size at the time of infection.
(Goo is an element, right? And he controls it, I guess? Right? Okay.)