I can't tell by the pics but I think that Warren may be right about the ivory or possibly bone. Can you see any veins or lines running through the piece? Ivory and bone will have distinct lines running the length of the piece.
Actually this is a pez dispenser that I have been trying to get rid of for a while, call me superstitious but it ain't been nothing but a pain to me, the only reason I am trying to sell it is to try to make up for some of the trouble. BUT...if it doesn't sell I'm burning it lol