<em>A clade is used to refer to all members of group of organisms that share the same ancestor.</em>
Animals are the only group of living organisms that are eukaryotic, multicellular as well as heterotrophic in nature.
They are eukaryotic because their cells have nucleus and membrane-bound organelles like mitochondrion and chloroplast.
They are multicellular because their bodies are made up of more than one cells. The simplest animal (sponge) is made up of several cells while the most complex animal (human) is made up of millions of cells.
Animals are heterotrophs because they lack the capacity to manufacture their own food. They depend on external source for their food. Particular, animals ingest their foods, digest it internally and egest undigested food/waste materials.
