Kukly are people and animals possessed by Chernobog in The Vanishing, the Stranger Things crossover mission. They move like puppets on strings, hit hard in melee and are weak to fire.
Kukly rush in with farm tools and blades and throw rocks from range. They're strong, so a group can wear you down fast.
Use fire. A flamethrower such as the Tostador burns through them, and incendiary ammo helps with any gun. Back up as you fight so they can't surround you.
Only in The Vanishing, alongside El Devorador.