Mimicry. The wendigo can mimic animal sounds and humanoid voices. A creature that hears the sounds can tell they are imitations with a successful DC 14 Wisdom (Insight) check.
Multiattack. The wendigo makes three attacks: one with its bite and two with its claws. If it can, wendigo uses its Staggering Roar instead of a Bite attack.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 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: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage. If the target is a Large or smaller creature that the wendigo already hit with two claw attack this turn, the target is grappled (escape DC 14). Until this grapple ends, the creature is restrained and the wendigo can't use its claws against another target.
Staggering Roar (Recharge 5-6). The wendigo emits a thundering roar. Each creature within 30 feet of the wendigo must succeed on a DC 14 Wisdom saving throw or take 14 (4d6) psychic damage and be stunned 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.