Dokkaebi

Invisibility Hat. Its hat allows it to turn invisible. Works for another only if dokkaebi formally allows that creature to borrow it. A creature wearing hat with permission can use its Invisibility action. If hat is not returned when requested hat loses all magical properties.

Wrestler. Advantage on Str (Athletics) checks made to grapple and ability checks and saves made to escape a grapple.

Multiattack. Three attacks with its club.

Dokkaebi Bangmangi. Melee Weapon Attack: +5 to hit, 5 ft., one target, 5 (1d4+3) bludgeoning damage. See below..

Invisibility. Magically turns invisible until it attacks or until its concentration ends (as if concentrating on a spell). Items wears or carries are invisible with it. Can't use this if it doesn't have its hat.