A symbiote, in Marvel Comics' fictional universe, is a living, sentient, extraterrestrial organism that bonds with other living organisms in order to survive. Since it has no classifying name, it is referred to as a symbiote because of its symbiotic relationships. Often symbiotes are called "living costumes" because of the way the amorphous creatures envelop their hosts. They have incredible adaptive attributes and quickly gain similar powers to the superhuman they bond to. They are extremely deadly and have murderous urges on a regular basis. Some symbiotes, like Venom and Carnage, are known to threaten to eat their victims' brains, among other organs (Venom has made regular threats to eat Spider-man's spleen), and Venom has been hinted to have eaten some of the criminals he kills to sate