Adhesive (Object Form Only). The mimicling can adhere to anything that touches it. A Medium or smaller creature adhered to the mimicling is also grappled by it (escape DC 12).
False Appearance (Object Form Only). If the mimicling remains motionless at the start of combat, it has advantage on its initiative roll. Moreover, if a creature hasn’t observed the mimicling move or act, that creature must succeed on a DC 18 Intelligence (Investigation) check to discern that the mimicling is animate.

Pseudopod. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2)
bludgeoning damage. If the mimicling is in object form, the target is subjected to its Adhesive trait.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature grappled by the mimicling.
Hit: 4 (1d4 + 2) piercing damage plus 2 (1d4) acid damage.

Shape Change. The mimicling polymorphs into an object 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.