Wendigo, Mist Walker

Wendigo Fever. Any Creature that is reduced to 0 HP by The Wendigo but not Cannibalized must make a DC 14 Constitution saving throw. On a failed save, the creature contracts Wendigo Fever. The DM can Dictate other situations that may require a creature to make this saving throw.

Cannibalize. When The Wendigo reduces a living creature within 5ft of it to 0 HP, it can use its bonus action to consume the corpse of the creature. When it does so regains HP equal to the consumed creature's Constitution Score.

Spider Climb. The Wendigo can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

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.

Mask 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.

Innate Spellcasting. The Wendigo's Spell Casting Ability is Wisdom (Spell Save DC 14). The Wendigo can innately cast the following spells, requiring no material components:

At Will:  Frostbite, Minor Illusion, Ray of Frost
3 per Day: Dispel Magic, Fog Cloud, Ice Knife, Misty Step, Ray of Sickness, Silent Image, 
1 per Day: Blindness/Deafness, Darkness, Elemental Bane [cold], Ray of Enfeeblement 

Multiattack. The Wendigo makes 2 claw attacks and a bite attack on its turn.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., 1 target. Hit: 17 (2d10+6) piercing damage.

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 15 (2d8 + 6) slashing damage. plus an additional 4 (1d6) cold damage.

Unnerving Howl. When the Wendigo damages a creature it can let out a horrific cry as a bonus action. Creatures within 30 feet of it must make a DC 16 Wisdom saving throw. On a failed save they are frightened of the Wendigo until the start of its next turn.

Dissipate (Recharge 6). The Wendigo transforms into toxic mist or reverts to its true form. Any equipment it is wearing or carrying is also transformed. It reverts to its true form if it dies.

While in mist form, the Wendigo is incapacitated and can’t speak. It has a flying speed of 30 feet, can hover, and can pass through any space that isn’t airtight. It has advantage on Strength, Dexterity, and Constitution saving throws, and it is immune to nonmagical damage.

While in mist form, the Wendigo can enter a creature’s space and stop there. Each time that creature starts its turn with the Wendigo in its space, the creature must succeed on a DC 12 Constitution saving throw or be poisoned until the start of its next turn. While poisoned in this way, the target is incapacitated.

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

Attack. The Wendigo lunges out and makes one claw attack with reach of 10 ft. 

Misty Step (Costs 2 Actions). Disappearing in a shroud of silvery mist, the Wendigo teleports 30 feet to an unoccupied space it can see.

Cantrip. The Wendigo casts one of its cantrips