They're from the clouds and they come to earth via the 무지개, 레인 보우 but as they slide down the 무지개, 레인 보우 their hair gets mixed up in the 색깔 that's why they have such colorful hair! ^^
They come from the minds of sick dumbfucks all around the world who are having problems with their lives, so they need to make other people feel bad in order to make themselves feel intelligent. Therefor, a troll is born.
Trolls originated from Scandinavian legends. They were essentially believed to live underground because they would turn to stone if ever exposed to sunlight (which, according to legend, is were mountains come from) They are basically Norse giants that come with many heads and a bad temperament.