Blinkepede

Immutable Form. The blinkepede is immune to any spell or effect that would alter its form.

Paralyzing Gaze: When a creature that can see the blinkepede's eye starts its turn within 30 ft. of the blinkepede, the blinkepede can force it to make a DC 12 Wisdom saving throw if the blinkepede isn't Incapacitated and can see the creature. On a failed save, the creature is paralyzed until the end of its next turn. Unless surprised, a creature can avert its eyes to avoid the saving throw at the start of its turn. If the creature does so, it can't see the blinkepede until the start of its next turn, when it can avert its eyes again. If the creature looks at the blinkepede in the meantime, it must immediately make the save.

Sting: +8 to hit, 1d4 + 4 piercing damage

Puppet Corpse: The blinkepede burrows into an intact corpse it can see within 5 feet of it and attaches itself to the corpse's spine. The corpse must be Large or smaller and be that of a beast or a humanoid. 

The blinkepede is now effectively the possessed creature. Its type becomes construct, and it gains a number of temporary hit points equal to the corpse's hit point maximum in life . 

While possessing the corpse, the blinkepede now controls the body but doesn't deprive the target of awareness. The blinkepede can't be targeted by any attack, spell, or other effect, and it retains its alignment, Intelligence, Wisdom, Charisma, and immunities to poison and psychic damage, and the charm, exhaustion, frightened, and poisoned conditions. It otherwise uses the possessed target's statistics, but doesn't gain access to the target's knowledge, class features, or proficiencies. 

The possession lasts until temporary hit points are lost (at which point the body becomes a corpse once more), the blinkepede ends it as a bonus action, the blinkepede is forced out by the Greater Restoration spell, or removed by succeeding on a DC 15 Wisdom (Medicine) check and cutting the blinkepede out with a sharp instrument, causing an additional 4d6 piercing damage to the host. When the possession ends, the blinkepede reappears in an unoccupied space within 5 ft. of the body. 

Spinal Tap. The blinkepede can partially burrow into an incapacitated creature, which must be Large or smaller and be that of a beast or a humanoid. The target succeed on a DC 12 Constitution saving throw or be puppeted by the blinkepede as it latches onto the target's spine and manipulates its nervous system; the target is incapacitated and loses control of its body. The blinkepede now controls the body but doesn't deprive the target of awareness.

While puppeting the target, the blinkepede can't be targeted by any attack, spell, or other effect, and it retains its alignment, Intelligence, Wisdom, Charisma, and immunities to poison and psychic damage, and the charm, exhaustion, frightened, and poisoned conditions. It otherwise uses the possessed target's statistics, but doesn't gain access to the target's knowledge, class features, or proficiencies. 

The possession lasts until the body drops to 0hp, the blinkepede ends it as a bonus action, the blinkepede is forced out by the Greater Restoration spell, or removed by succeeding on a DC 15 Wisdom (Medicine) check and cutting the blinkepede out with a sharp instrument, causing an additional 4d6 piercing damage to the host. When the possession ends, the blinkepede reappears in an unoccupied space within 5 ft. of the body.