GREY ZONE CREATURES. “In eukaryotes as well, the distinction between unicellular and multicellular is not always completely clear. For example, the social amoeba, Dictyostelium discoidium, is unicellular during part of its life cycle, but upon starvation, cells aggregate and develop into a multicellular motile slug, then fruiting body. Stalk cell death is programmed and is characterized by some classic features of POD.” (POD = programmed organismal death).