Troll

A troll is a type of Human or humanoid creature often storied in Earth mythology. Trolls originated in the myths of Nordic Europe, some consider them to be the enemies of gnomes.

When the USS Enterprise (NCC-1701) visited Valerian in the 2270s, it found that a Federation colony had been targeted by gnomes, who were turning the colonists into trolls in order to stave off further visits from outsiders.