Amarok, The Guardian Wolf of Nunavat

Keen Hearing and Smell. The wolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Lone Wolf. The wolf has advantage on attack rolls against a creature if no ally is within 5 feet of the creature.

Change Appearance. The wolf can use its action to polymorph into a Medium humanoid it has seen, or back into its true form. Its statistics, other than its size, are the same in each form. It reverts to its true form if it dies.

Wild Shape.  The wolf can use its action to magically assume the shape of a beast that it have seen before for an unlimited number of times. It can transform into any beast that has a challenge rating of 6.

It reverts to its normal form by using a bonus action on its turn and automatically revert if it fails unconscious, drop to 0 hit points, or die.

Apply the same rules as the druids, except:

• The wolf can use its special senses (truesight) instead of the beast's sense.

Legendary Resistance (3/Day). If the wolf fails a saving throw, it can choose to succed instead.

Magic Resistance. The wolf has advantage on saving throws against spells and other magical effects.

Magic Weapons. The wolf's weapon attacks are magical.

Innate Spellcasting. The wolf's innate spellcasting ability is Wisdom (spell save DC 21). The wolf can innately cast the following spells, requiring no material components:

At will: druidcraft, fog cloud (6th-level version), mending

3/day: animal friendship, sleet storm

1/day: goodberry, pass without trace

Multiattack. The wolf makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 40 (6d10 + 7) piercing damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be knocked prone.

Claws. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 52 (10d8 + 7) piercing damage.

Parry. The wolf adds 5 to its AC against one melee attack that would hit it. To do so, the wolf must see the attacker.

The wolf 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 wolf regains spent legendary actions at the start of its turn.
Attack. The wolf makes one attack.

Move. The wolf moves up to its speed without provoking opportunity attacks.

Trembling Strike. (Costs 1 Action) The empyrean strikes the ground with its maul, triggering an earth tremor. All other creatures on the ground within 60 feet of the empyrean must succeed on a DC 21 Strength saving throw or be knocked prone.