That all depends on the bull itself. Not all bulls have horns, and not all bulls weigh 2000 lbs. It also depends on the breed of the bull and its temperament. Normally bulls, as prey animals, choose to flee from a predator like a polar bear rather than stand and fight, and a polar bear wouldn't know what to make of a bull in the first place, since they don't actively hunt cattle, but instead seals and walruses, and maybe the occasional caribou and muskox.
Maybe if the bull was a little Dexter the polar bear might win. But if it was against a 2200 lb Spanish Fighting Bull the polar bear may loose. The polar bear may even lose if it's against a hot-tempered Chianina bull. So who knows?
A polar bear would totally lose because a rhino would charge at the polar bear and knock it with its horn.
Polar bear.
polar bear
This fight would never happen, no matter how you look at it.
a polar bear will most likely win in a fight against a grizzly bear
It depends on the health and size of the two animals, and the position of where are they attacking. If the ox struck the polar bear with its head or knocked its chest, the ox would win the fight. If the polar bear swiped and clawed the ox to death, the ox would be a meal of the polar bear.
I don't know if such a fight has ever happened or ever will, but my guess is that the polar bear would win. Both animals are very strong, but the polar bear has bigger claws and teeth.
A polar bear would win the fight on land if it clawed the crocodile's head and flipped its body to claw its stomach. In water, the crocodile would definitely win the fight.
Polar bear, they are known as the most carnivorous bear.
Hard to say in a real fight, both are large powerful bears, but in interactions between the two species, brown/grizzlies seem to dominate the polar bears.
It is highly likely that the elephant would win the fight. Elephants have thick, defensive hide and tons of muscles to protect itself from claws and teeth, which would make it not get injured by the polar bear. The strong muscles of the elephant's head is good enough to kill the polar bear whenever it hits the polar bear. If the elephant has sharp tusks, it would definitely win by goring the polar bear to death. A cow elephant or a bull elephant can crush a polar bear to death.
The polar bear. It is larger, has sharper claws, stronger jaws, sharper teeth, better fighter, and has thicker muscles with better killing skills.