Shapechanger. The mimic can use its action to polymorph into an apple bobbing tub 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 Huge or smaller creature adhered to the mimic is also grappled by it (escape DC 13). Ability checks made to escape this grapple have disadvantage.

Acid Splash (Object Form Only). A creature that touches the mimic or hits it with a melee attack while within 5 feet of it must make a DC 10 Dexterity saving throw.  On a failure, it takes 4 (1d8) acid damage and any nonmagical weapon made of metal or wood that hits the mimic corrodes.  After dealing damage, the weapon takes a permanent and cumulative −1 penalty to damage rolls. If its penalty drops to −5, the weapon is destroyed.

Bobbing for Acid (Object Form Only). A creature that ends its turn grappled by the mimic takes 4 (1d8) acid damage.

False Appearance (Object Form Only). While the mimic remains motionless, it is indistinguishable from an ordinary apple bobbing tub.

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

Pseudopod. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature that is grappled by the mimic. Hit: 7 (1d8 + 3) piercing damage plus 4 (1d8) acid damage.

Acid Spray (Recharge 5–6). The mimic sprays acid from its basin in a 15-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw. On a failure, a creature takes 4 (1d8) acid damage and any nonmagical armor they are wearing corrodes.  The armor takes a permanent and cumulative −1 penalty to AC. If its penalty drops to −5 or causes the creature's AC to drop below its unarmored AC, the armor is destroyed.  On a successful save, a creature takes only half damage, and isn't subject to the AC penalty.