I would say a polar bear because it can move much quicker and with much more ease.
A polar bear is able to win in a fight against a small walrus, but usually loses to a bigger walrus such as a mother.
It could go either way. However, it is most likely that the walrus wins, because of it's think oily skin and tusks
On land, the walrus and/or bull, no question. Those large tusks from the walrus and large horns from the bull (if the bull is indeed horned) are more than enough to intimidate and/or kill a polar bear. In the sea, no body because the walrus would swim away faster than the bear could catch it, the bull would drown, and the polar bear would be left holding the bag, so to speak.
In a fight, 6 pumas would likely overwhelm and defeat a walrus due to their speed, agility, and hunting skills. Walruses are adapted for aquatic environments and lack the agility and predatory instincts of pumas.
Walrus would win due to it weight
This fight would never happen, no matter how you look at it.
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.
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 killer whale, easily. They are three times the size of a Walrus and a Walrus has no teeth.
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.
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.
polar bear