The two back legs of the elephant contain knees complete with kneecaps. The same area on the front legs acts more like a wrist joint. Elephants rise by propping on their front wrists and using the knees of the back legs to stand upright.
Elephants are the largest land mammals alive, with the biggest weighing approximately 15,000 pounds. They have many unique features. The elephant trunk is a fusion of the nose and upper lip. It is manipulated by thousands of tiny muscles. The elephant replaces its teeth periodically; new ones grow in the back and ones in the front are shifted out. Elephant tusks are used for fighting, digging and eating.