A kingdom of diverse, multicellular organisms that exhibit a broad range of physical and behavioral traits, including primates (such as humans, monkeys, and apes), mammals (warm-blooded vertebrates with hair or fur), arthropods (invertebrates with exoskeletons, segmented bodies, and jointed appendages like insects, spiders, and crustaceans), and amphibians (cold-blooded vertebrates that spend some of their life in water and some on land, such as frogs and salamanders). This kingdom embodies all known forms of life classified as animals.