Unusual Nature. The parasite doesn't require air or sleep.
Cling. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit:12 (3d6 + 2) necrotic damage, and the parasite attaches to the target. While attached, the parasite can't make Cling attacks. The parasite can detach itself by spending 5 feet of its movement. As an action, a creature within reach of the parasite can try to detach it, doing so with a successful DC 14 Strength check.
Consume Life. The parasite deals 12 (3d6 + 2) necrotic damage to one creature it is physically attached to, provided that creature isn't a Construct or an Undead. The parasite regains hit points equal to the damage taken.
Suggestion (Psionics; 1/Day). The parasite casts the suggestion spell, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 13).
A puppeteer parasite looks like a rubbery amoeba the size of a dinner plate. Its dorsal surface is soft and glossy, while its ventral surface is lined with bony hooks. The parasite uses its hooks to attach to a wall or ceiling until suitable prey passes nearby.