Zetsu is a missing-nin from the Hidden Grass Village and currently serves as a spy and cleanup crew for the Akatsuki organization. He disposes of bodies not meant to be found (he eats them, he's a cannibal) and acts as a lookout a lot. His position in Akatsuki is unclear, since other members sometimes talk to him as if he's a higher ranked Akatsuki member. He has a giant Venus Flytrap around his head and shoulders, but what this exactly is and does is unknown. It could be a summon, or some kind of parasite. We also hear Zetsu talking to himself a lot, he seems to have a split personality. And since his face is half black, and half white on the other side, this is probably the case. He has his Akatasuki ring (boar) on his right little finger and first appears in Naruto watching the fight between Naruto and Sasuke. Much else isn't known about Zetsu, he remains a mysterious Akatsuki member.