Shapechanger The compound mimic can use its action to polymorph into objects of the same size 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 The compound mimic adheres to anything that touches it. A huge or smaller creature adhered to a large compound mimic or a gargantuan or smaller creature if the compound mimic is huge is also Grappled by it (escape DC 16). Ability Checks made to escape this grapple have disadvantage.

False appearance (Object Form Only) While the mimic remains motionless, it is indistinguishable from an ordinary object.

Grappler The mimic has advantage on Attack rolls against any creature Grappled by it.

Hardy While in its conjoined form the compound mimic regains 1d10 HP at the start of its turn.

Actions

Conjoined Form When in its conjoined form, as an action the compound mimc can split into three individual mimics, each with the statistics of a mimic; the Compound Mimic’s HP is equally distributed amongst them.

The Compound Mimic can return to its conjoined form for an action, so long as its three mimics are within 15ft of each other. The large creature’s HP is the sum of the mimics' current HP. The large mimic occupies the nearest empty space equidistant from the mimics.

Absorb When in its conjoined form, the compound mimic can absorb any mimic it can see within 15 feet of it. The absorbed mimic’s current HP is added to the compound mimic’s HP, not exceeding its maximum HP.

If a large compound mimic absorbs three or more mimics, it grows in size to become huge. The huge compound mimic’s AC is 19 and its speed is 10ft.

Pseudopod Melee Weapon Attack: +8 to hit, reach 15 ft., one target (large), two targets (huge), conjoined form only. Hit: 21 (3d10+5) bludgeoning damage. On a hit, the mimic may choose to apply the Adhesive trait and grapple the target.

Pull The compound mimic can pull all targets grappled by a pseudopod up to 15ft towards its mouth.

Bite Melee Weapon Attack: +8 to hit, reach 5 ft., one target, conjoined form only. Hit: 21 (3d10+5) piercing damage plus 16 (3d10) acid damage. If the target is a Medium or smaller creature, it 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 14 (4d6) acid damage at the start of each of the mimic’s turns.

A large compound mimic can swallow 1 medium, 3 small or 10 tiny creatures. A huge compound mimic can swallow 1 large, 2 medium, 6 small or 20 tiny creatures.

Fighting from Within If the compound mimic takes 15 damage or more in a single turn from a creature inside of it, the mimic must succeed on a DC 21 Constitution saving throw. If it fails, it must regurgitate all swallowed creatures at the end of that turn. All regurgitated creatures 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 ft of movement, exiting prone.

Legendary Actions

The compound mimic gets two legendary actions per round, which it can spend doing any of the following:

• Conjoined Form
• Absorb
• Pseudopod
• Pull
• Bite
• Swarm (costs 2 legendary actions) The compound mimic summons 1d4 mimics to the area. The new mimics arrive on the compound mimic’s next turn and take their turn on its initiative count.