What animal can defeat an adult male polar bear?

In Polar Bears' native environment? Almost none, except may be Oras or large sharks when polar bears were swimming in open ocean, which they often do. In a man made cage fight? I can think of Grizzlies, tigers, Lions, even a huge python, large crocodiles, or some venomous creatures. read more

Elephants, Hippos, and Rhinos can all easily take down a grizzly/polar bear 9/10. Adult male Lions and Tigers CAN take down a grizzly or polar bear. It won't be a majority, but they have the tools to take them down. read more

Plus, polar bears are all muscle, they have to take down seals and walrus, and even will stalk and kill humans. Plus, polar bears are hustlers. They eat all meat and are ferocious hunters, while grizzles lounge around eating berries and fish. read more