(i) Unicellular Animal: They are protocellular and their body is made up of only one cell. Protozoa are unicellular organisms. Such as Amoeba (Amoeba proteus), Malaria parasite (Plasmodium vivax), Entamoeba histolytica etc.
(ii) Multicellular Animal: They are true cells and their body is made up of multiple cells. Animals of the order Metazoa, Porifera and Chordata are multicellular. Such as Hydra- (Hydra vulgaris), Ilisha (Tenualosa ilisha), Doel (Copsychus saularis) etc.