Polar bears hunt humans, I think they are the only animal that sees us food. My friends aunt had to shoot one once, it was way back in the 50's. She was alone in a smallish hut - was out with engineer husband who was away. Unfortunately it got wind of her and started taking her home apart. Once they have you that's it, they will keep going until they get you, she had no choice. It's funny when you see this sweet little old lady...she feels real regret but lived there for many years and knew she had no chance they are trully lethal.
We have foxes in our garden, they are everwhere in london and dont have to hunt there is so much in the trash! I have seen them carrying shopping bags in their mouths happily trotting home...