Bear Abomination

Keen Smell. The creature has advantage on Wisdom (Perception checks) that rely on smell.

Rotten. After it's health drops below 50% much of it's sagging skin has been removed exposing it's rotten flesh underneath. Any creature that ends their turn within 5ft of the abomination must take 2d4 poison damage.

Multiattack. The abomination makes two claw or Greataxe attacks

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage. If the target is a humanoid, it must succeed on a DC 14 Constitution saving throw or be poisoned.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Greataxe. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 10 (1d12 + 4) slashing damage.

The Abomination can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. The Abomination regains spent legendary actions at the start of its turn.

Bite.  Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) piercing damage. If the target is a humanoid, it must succeed on a DC 14 Constitution saving throw or be poisoned.

Bloody Roar  (2 actions) Each creature that is within 30 feet of the Abomination and aware of it must succeed on a DC 14 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the creatures Frightful Presence for the next 24 hours.