Ancient Wendigo Dragon

Undead. The dragon does not require air to exist.

Legendary Resistance (4/Day, or 5/Day in Lair). If the dragon fails a saving throw, it can choose to succeed instead.

Insatiable Hunger: At the start of its turn, the dragon regains 20 hp if any creature within 30 ft is:

• below half hp, or
• suffering exhaustion

Aura of Starvation (60ft): Creatures must make a DC 20 Con save at the start of their turn:

• Fail: Gain 1 level of exhaustion
• Fail by 5+: gain 2 levels of exhaustion
• Creatures 3+ exhaustion also become frightened of the dragon.

Predator of the Doomed: The dragon has advantage on attacks against

• Frightened, exhausted, or prone creatures
• creatures below half HP

Critical hits occur on 19-20 against such targets

Multiattack. The dragon makes 4 attacks:

Bite. Melee Attack Roll: +16 to hit, reach 15ft. Hit 40 (4d10+9) piercing + 20 necrotic

If target is below half hp:

• Must save DC20 Con save or gain 1 level of exhaustion
• Dragon heals 30 hp

Claw. +16 to hit, reach 15ft. Hit: 30 slashing, 10 cold.

Tail. +16 to hit, reach 20ft. 38 bludgeoning. Target must succeed DC 20 Str Save or be nocked prone.

Breath weapon: Cataclysm of Hunger (Recharge 5-6):90ft cone. 

• DC 21 Con Save
• 80 cold, 50 necrotic damage
• on failure:
  • Gain 2 levels of exhaustion
  • Frightened for 1 minute.

Devour Essence (Recharge 5-6): 

One creature within 15ft:

• DC 21 Con Save
• 80 necrotic damage
• Gain 1 level of exhaustion
• Dragon heals full damage

If this kills the target:

• Soul consumed (only a wish spell can restore)
• Dragon gains +10 to all damage dealt for 1 minute.

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, the dragon can expend a use to take one of the following actions. The dragon regains all expended uses at the start of each of its turns.

Pounce. The dragon moves up to half its Speed, and it makes one Bite attack.

Consume fear (2 actions). One frightened creature takes 30 psychic damage. Dragon heals same amount.