Ok, the cats were mentioned. They are predators.
Hippos are not. Neither are Elephants or Water Buffalo.
Crocks and Gators are predators but I look at them more like opportunists.
We've got snakes and Lizards and insects that are predatory, but are also opportunists.
There are Birds of prey, and big Sharks, even Squid. Orca are actually pretty particular at what they eat and even though they're dubbed the 'Killer Whale', haven't been predator toward man in -forever.
Any of the large cats are Bad A$$'s, and pound for pound there are very few even matchups. Including Mountain Lion vs Wolf. I've got to agree with STEVELYN in an earlier post, "In the polar bear's world, everything that isn't another polar bear is something to eat."
Because even in a Lion's or Tiger's world, everything that roams the land is not food. From what I've read, for the most part, Tigers don't mess with primates! Cats support the 'Strong shall survive' rule. The weak, the slow, those are the easy prey of cats. Discovery Channal ran a simulated show/series a while back with a Grizzly vs Tiger/Lion. IIRC the Bear won both times. There were several other simulations.
Polar Bears just don't care. If he can smell you, (from four miles away), you're on the dinner menu. Now that's a true predator.
And what's this I've heard? Polar Bears crossbreading with Grizzly's?
-Steve