If you were looking for something to take down a Polar Bear, I'd actually wager money on a Grizzly. Polar bears tend to be bigger, but Grizz got bigger claws and a much stronger skull. The thing is on that omnivore life too, so while the Polar need a quick energy boost to get back in the fight, my homie the grizz can just pop a few blueberries like tic tacs and good to go.
Polar bear also not use to fighting enemies the same size as itself. Grizzlies are always fighting over territory and food with other grizzlies, so they know very well about fighting a nikka its own size, damn near like they train and shyt. My vote goes to the Grizzly as the coldest mufukka walking the earth.