zetsu come from the cells of a wood eliment character and the 10 tails shell black half was made by madara they are also one of the main parts of akatsukis army (10000) the 3 main ones are white zetsu spiral zetsu (made by shell)and black zetsu(made by madara) all 3 help obito spiral fused with him and the other to (can also fuse) help him with madaras plans