Some characteristics include:
All animals are multicellular, eukaryotic heterotrophs, they have multiple cells with mitochondria and they rely on other organisms for their nourishment.
Adult animals develop from embryos: small masses of unspecialized cells
Simple animals can regenerate or grow back missing parts
Most animals ingest their food and then digest it in some kind of internal cavity. Somewhere around 9 or 10 million species of animals inhabit the earth.
About 800,000 species have been identified.
Biologists recognize about 36 separate phyla within the Kingdom Animalia.
Hope this helps,
kwrob