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

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

Innate Spellcasting. The mimic's innate spellcasting ability is Constitution (spell save DC 11). The mimic can innately cast the following spells, requiring no material components:

1/day each: stinking cloud (centered on self, moves with the mimic when the mimic moves)

Toxic Smoke. Whenever a creature uses the mimic as a smoking pipe, that creature must make a DC 11 Constitution saving throw.  On a failure, the creature is poisoned for 1 hour.  While poisoned this way, a creature has disadvantage on saving throws against spells cast by the mimic.

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.  The mimic can choose to deal fire damage or poison damage instead of acid damage.