Shapechanger. The mimic can use its action to polymorph into a set of bed linen (pillows and blankets) 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 (Object Form Only). The mimic adheres to anything that touches it. A creature adhered to the mimic is also grappled by it (escape DC 14). Ability checks made to escape this grapple have disadvantage.

Damage Transfer. While it is restraining a creature, the mimic takes only half the damage dealt to it, and the creature restrained by the mimic takes the other half.

False Appearance (Object Form Only). While the mimic remains motionless, it is indistinguishable from an ordinary set of bedding.

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

Innate Spellcasting. The mimic's innate spellcasting ability is Wisdom (spell save DC 12). The mimic can innately cast the following spells, requiring no material components:

At will: feather fall (self only)

1/day each: sleep

Pseudopod. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.

Smother. Melee Weapon Attack: +5 to hit, reach 5 ft., one Large or smaller creature. Hit: If the mimic is in object form, the target is subjected to its Adhesive trait and is restrained. Until it escapes, the target is blinded and at risk of suffocating, and the mimic can't smother another target. In addition, at the start of each of the target's turns, the target takes 13 (2d8 + 4) bludgeoning damage.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) piercing damage plus 9 (2d8) acid damage.