Model bodies not rendering

Any model inside the game renders incorrectly. Whenever I entered the game start screen, only the head of the player model was being rendered. When I created a Creative world and spawned a Phantom using a Spawn Egg, only the Phantom's head was being rendered. I continued walking through my world and found a sheep, whose head was the only part of the body being rendered.

I attached two screenshots showing two of the three mentioned cases.