As ostentatious as it is deadly, the coffin mimic fits right in with the rest of a vampire crypt’s decor. This is the point, of course. The monstrosity exudes a coppery perfume that most undead find particularly irresistible once they catch a whiff. This scene lures the creature in, invites it to lay down, and gives the coffin mimic an easy meal. If that doesn’t work, the shapeshifter isn’t shy to resort to violence. The coffin doesn’t just feed on the undead. Pesky heroes poking around in its hunting grounds taste just as good.

Macabre Vamp-Trap. As her fight against the vampires that took everything she had neared its in, La Contessa grew frustrated as they went to ground to wait out her wrath. While the alchemist took profane steps to prolong her life, she also bred further chemical-manipulated mimics to aid her fight. The most successful has been the coffin mimic. These wonderful abominations burrow into the dusty tombs where vampires and the like hide from the sun and set themselves up to resemble the other resting places. Then it is just a matter of temptation and patience.

Coffin Mimic

Medium monstrosity (shapechanger), neutral

Armor Class 14 (natural armor)

Hit Points 119 (14d8 + 56)

Speed 15ft

Burrow 20ft

Str 18 Dex 10 Con 19 Int 5 Wis 15 Cha 8

Saving Throw Wis +5, Char +2

Damage Resistances poison

Damage Immunities acid, necrotic

Condition Immunities charmed, paralyzed, petrified, poisoned, prone

Senses darkvision 60ft passive Perception 12

Languages -

Challenge 8 (3900 XP)

Shapechanger.

TThe coffin can use its action to polymorph into an empty coffin or back into its true, amorphous form. Its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Adhesive (Coffin Form Only).

The coffin adheres to anything that touches it. A Huge or smaller creature adhered to the coffin is also grappled by it (escape DC 15). Ability checks made to escape this grapple have disadvantage.

Blood Bloom.

Any undead creature that starts its turn within 10ft of the coffin must succeed on a DC 15 Wisdom save or be Charmed for the next minute. At the end of each of its turns, an affected creature may repeat this save with the effect ending on success.

Once a creature saves against Blood Bloom it is immune to the effect for 24 hours.

False Appearance.

While the coffin remains motionless in its coffin state, it is indistinguishable from an ordinary, if extravagant, coffin​.

Grappler.

The coffin has advantage on attack rolls against any creature grappled by it.

Magic Weapons.

The coffin's weapon attacks are magical.

Actions

Multiattack.

The coffin can make three pseudopod attacks as one action.

Pseudopod.

Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) bludgeoning damage. If the creature is in its cart form, the target is subjected to its Adhesive trait.

Bite.

Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) piercing damage plus 4 (1d8) acid damage.

Swallow.

The coffin makes one bite Attack against a Medium or smaller target it is Grappling. If the Attack hits, the target is swallowed, and the grapple ends. The swallowed target is Blinded and Restrained, it has total cover against attacks and other Effects outside the coffin, and it takes 13 (4d6) acid damage at the start of each of the coffins's turns. The coffin can have only one target swallowed at a time.

A swallowed creature can attempt to escape (DC 15) as its action, exiting in a square within 5ft of the coffin if successful.

Creatures that are swallowed by the coffin lose their shapechanger trait, if they have it and revert to their natural form.