Board Thread:Naruto Discussions/@comment-1926479-20140604055230/@comment-1512913-20140605094334

What makes Zetsu, well, Zetsu in the first place is the Shinju/Gedo Mazo, Hash cells are optional to the whole process. Madara's Zetsu were clones of Hashirama, but every person will have turned into Zetsu in the cocoon.