Briefly discuss why you are proud to be a mammal and give examples of mammals that habitat various water kingdoms? Solution Mammals are vertibrate, endothermic amneotes possessing neocortex, hair, three middle year bones and mammary glands. As mammals are endothermic they can live almost all type of environments. Produce milk, to feed babies. There are 4000 different species of Mammals. The smallest mammal is Hog nosed bat and largest one is Blue whale. Some mammales habit to the water bodies. Eg. Blue whale, Dolphins, polar bears, pinnipeds, dugongs etc..