Wendigo

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

Masks of the Wild. The wendigo can attempt to hide even when it is only lightly obscured by foliage, heavy rain, falling snow, mist, or other natural phenomena.

Ambusher. The wendigo has advantage on attack rolls against any creature it has surprised.

Stalking the prey. The wendigo as advantage on stealth checks in forest environment.

Big Eater. The Wendigo can eat an humanoid corpse to increase its maximun hit points be 1d12 and grow 1d4 feet in height to a maximun of 28 feet.

Regeneration. The Wendigo regains 10 Hit Points at the start of its turn. If the troll takes fire damage, this trait doesn't function at the start of the Wendigo's next turn. The Wendigo dies only if it starts its turn with 0 Hit Points and doesn't Regenerate. (Only at 28 feet)

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

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 16 (4d6 + 2) piercing damage and 10 (3d6)  necrotic damage. The wendigo regains hit points equal to necrotic damage dealt, unless the target is a construct or undead.

Claw. Melee Weapon Attack: 13 to hit, range 5 ft., one target. Hit: 18 (4d6 + 4) slashing  damage.

Frightful Presence. Each creature of the wendigo's choice that is within 60 feet of the wendigo and aware of it must succeed on a DC 17 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 wendigo's Frightful Presence for the next 24 hours.

Dash. The Wendigo can dash as a bonus action