Shapechanger. The mimic can use its action to polymorph into a tool 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.

Craftsman. The mimic is considered proficient with any tool it polymorphs into.

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.

Innate Spellcasting. The mimic's innate spellcasting ability is Intelligence. The mimic can innately cast the following spells, requiring no material components:

At will: mending, fabricate

Repair. When the mimic casts mending on a magic item or construct, it restores magic to such an object.  Additionally, when the mimic casts mending on a construct, the construct regains 3 (1d4 + 1) hit points.

Wrench in the Works. A construct or mechanical device (such as a crossbow or firearm) grappled by the mimic is also paralyzed and rendered inoperable until the grapple ends.  This effect ignores immunity to the paralyzed condition.

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.

Handaxe. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) slashing damage