Quackthulhu

 is a gigantic mutated duck created by Matthew Mercer.

Appearance
Quackthulhu is a massive, swollen duck-like creature of ill green feathers and flesh, burning red eyes, and four terrible whipping tentacles protruding from its body. A glowing stone that fell as a shooting star is embedded within its back, with dark veins writhing around where it pierces its body.

Abilities
Matt published Quackthulhu's stat block on Twitter. The following abilities were demonstrated in.


 * Legendary resistances (3x per day)
 * Damage resistances: bludgeoning, piercing, and slashing from non-magical weapons
 * Damage immunities: necrotic
 * Multiattack: each tentacle can attack and attempt a grapple each turn
 * Soul-Wrenching Quack: paralyzes opponents failing a DC 16 wisdom saving throw
 * Legendary Actions (3x per round):
 * Ground Slam - opponents failing a DC 14 strength saving throw are pushed 10 feet away
 * Tentacle attack
 * Ability to charm/take control of Lionel, possibly through his duck totem connection

Quackthulu was an ordinary duck until a meteor crashed into its duck pond, implanting itself into his back, and mutating it into a gigantic aberration. The Darrington Brigade killed it after a long, hard-fought battle, removing the meteor to take back to Doolan Tversky for a 10,000 gp reward.