Invisible Mimic

Actions

Pseudopod. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.   Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) piercing damage plus 9 (2d8) acid damage.   The mimic can move into a medium or smaller creature's space. When it does so, the creature must succeed on a DC 16 Dexterity saving throw or be swallowed by the mimic. A swallowed creature is blinded and restrained, it has total cover against attacks and other effects outside the mimic, and it takes 7 (2d6) acid damage at the start of each of the mimic's turns.   If the mimic takes 10 damage or more on a single turn from a creature inside it, the mimic must succeed on a DC 21 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the mimic. If the mimic dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 20 feet of movement, exiting prone.

Now you see it. Now you're being digested by it.