Shapechanger. The mimic can use its action to polymorph into a desktop or laptop computer 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 Large or smaller creature adhered to the mimic is also grappled by it (escape DC 12). 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 desktop or laptop computer.

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

Innate Spellcasting. The mimic's innate spellcasting ability is Intelligence (spell save DC 15, +7 to hit with spell attacks). The mimic can innately cast the following spells, requiring no material components:

At will: encode thoughts, lightning lure, sending, shocking grasp, vicious mockery

3/day each: comprehend languages, identify, legend lore, locate creature, locate object

1/day each: eyebite, modify memory, nondetection (self only), scrying, tiny servant

Pseudopod. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage plus 3 (1d6) acid damage or lightning damage (mimic's choice).

Upload. The mimic attempts to infect a Construct or system with living malware.  The system must be on the same plane of existence as the mimic, and the mimic must be aware of the system to target it.  The target it must make a DC 15 Intelligence saving throw or be infected with mimicware.

Mimicware is a Tiny construct with AC 5, 1 hit point, a 1 (−5) in every ability score, and a speed of 0 feet. Mimicware cannot exist outside of a system.  While infecting a target, mimicware has total cover against attacks and other effects outside the infected target and is immune to all damage that isn't force or lightning damage. 

When the system the mimicware is infecting is subjected to force or lightning damage, the mimicware takes half that damage.  While a construct or system is infested by mimicware, it suffers disadvantage on Intelligence ability checks and saving throws.

Hack.  The mimic attempts to gain control over a Construct or system it has infected with mimicware.  The target must make a DC 15 Intelligence saving throw.  On a failed save, the system becomes attuned to or magically bound to the mimic, ignoring or overriding any previous attunement or binding. 

As long as the system and the mimic are on the same plane of existence, the mimic can telepathically command the system, which obeys to the best of its ability.  The system remains under the mimic's control until a creature not under mimic's control succeeds on a DC 15 Intelligence check, with disadvantage, to cleanse the system of the mimic's malware and control.