Affects Version/s: Minecraft 1.13-pre1
Fix Version/s: None
THIS IS THE SAME AS MC-129612, WHICH IS MARKED AS CANNOT REPRODUCE. I COME TO 1) SHOW YOU THE WAY TO REPRODUCE IT; 2) CLAIM THAT THE ISSUE ISN'T ON THE COW ITSELF BUT ITS HITBOX.
Make a terrian and spawn a cow like Screenshot 1.
Put the cow on fire using flint and steel.
Notice how the cow will rotate rapidly above a 1*1 block of water instead of going into the larger pond like Screenshot 2 & 3.
EDIT: For sheeps and pigs, they rotate for a round or two, and then sink into the water block below.