Shapechanger. The mimic can use its action to polymorph into a rat or mouse trap 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 Medium or smaller creature adhered to the mimic is also grappled by it (escape DC 11). 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.

Surprise Attack. If the mimic surprises a creature and hits it with its bite during the first round of combat, the target takes an extra 7 (3d4) piercing damage from the attack.

Pseudopod. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 3 (1d4 + 1) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 3 (1d4 + 1) piercing damage plus 2 (1d4) acid damage.  If the mimic is in object form, the target is subjected to its Adhesive trait.

Reset Trap. The mimic opens its maw and tenses its muscles.  The next time it uses its Bite it deals an extra 7 (3d4) piercing damage on a hit.

Spring Trap. If the mimic's last action was its Reset Trap, when a creature the mimic is grappling escapes the mimic's Adhesive or hits the mimic with a melee attack while within 5 feet of it, the mimic can use its Bite against that creature.