David killed a bear (and a lion) with his bare hands.

David said unto Saul, Thy servant kept his father's sheep, and there came a lion, and a bear, and took a lamb out of the flock ... Thy servant slew both the lion and the bear ... The LORD ... delivered me out of the paw of the lion, and out of the paw of the bear. 1 Samuel 17:34-38

When 42 little children made fun of Elisha's bald head, he cursed them in the name of the Lord, and two bears came out of the forest and ripped them apart.

As he [Elisha] was going up by the way, there came forth little children out of the city, and mocked him, and said unto him, Go up, thou bald head; go up, thou bald head. And he turned back, and looked on them, and cursed them in the name of the LORD. And there came forth two she bears out of the wood, and tare forty and two children of them. 2 Kings 2:23-24

Someday cows and bears will eat and lie down together.

The cow and the bear shall feed; their young ones shall lie down together. Isaiah 11:7

And God will tear people apart like a mother bear who has lost her cubs.

I [God] will meet them as a bear that is bereaved of her whelps, and will rend the caul of their heart. Hosea 13:8