From reading lots of sources I can say that he is said to eat bodys linking to the Akatsuki.
Kishimoto Masashi (author) had originally planned for the akatsuki to be a group of monsters and each character represented something (zetsu = Plant) zetsu was one of them. But he changed the idea of the akatsuki, and he like Zetsu so much he decided to keep him.
Zetsu comes in episode 142 naruto shippuden Japanese book!!!(This is the main part)!!!
Zetsu's ring is green, and he wears it on the right little finger.
This happened in Naruto Shippuden Chapter 678, Black Zetsu Betrays Madara.
Yes, Zetsu does have arms, he just hasn't had a chance to use them yet becasue there hasn't been an opertunity where he can use them , when we can see.
Zetsu is a cannibal he eats humans.
it's said that his body wasn't found so zetsu could of aten him who knows what happened to itachi
Zetsu is half white and half black because (SPOILER ALERT) white Zetsu is an artificial life form that was created by Madara Uchiha with Hashirama Senju's DNA. When Madara was dying (the proper one, if you didn't know, not the re-encarnated one or Tobi/Obito pretending to be him) he infused part of his will into White Zetsu, creating his other personality, Black Zetsu.
Zetsu is still alive, for now.
Zetsu was created from Hashirama Senju's cell.
Sasuke killed Zetsu, It's highly debated that Zetsu was pulling off a Bunshin however.
naruto is way stronger zetsu can't fight
Zetsu likes pie,but only human flavor.
There is no official information available about Zetsu's birthday.
Yes, Zetsu is a medical ninja but you don't see him do it though.
Konan found zetsu too be usefull. by that I mean he can be a spy for her.
Zetsu's Ring Has The Word Kai (Boar) Its A Hand Sign