The Mother Grizzly Bear is one of the scariest antagonists of the films Man in the Wilderness, and The Revenant.
On the way to the Yellowstone River area, while hunting for food near the Grand River, Glass disturbed a female grizzly bear and her two cubs. The bear savagely attacked Glass, probably out of her protective maternal instinct.
The Mother Grizzly Bear has the following powers and abilites: Sharp teeth Sharp claws Dangerous mauling
Glass and the other men managed to kill the bear, but Glass was left badly mauled with a broken leg, and cuts that were so deep they exposed his ribs, almost torn off his scalp and ripped the flesh off his back.
The Mother Grizzly Bear has the appearance of a normal grizzly bear and therefore doesn't have a brief description, unless you look the Wikipedia article for grizzly bear.