A broad biological classification of diverse, multicellular organisms that exhibit specific characteristics, such as the ability to move independently and rapidly, the need to consume food or other organisms for energy, and the capability of sensing and responding to their environment. This category includes species from various taxonomic groups, like cnidarians, which are largely aquatic and possess stinging cells; mammals, characterized by their ability to regulate body temperature and nurse their young; arthropods, marked by their segmented bodies and exoskeletons; and amphibians, which typically live both on land and in water during different stages of their life cycle.