I've drawn a huldra a few times, and searching for huldra will undoubtedly only give to female hits, but they also have male equivalents, the huldrekarl (Literally "huldra guy").
They're not as popular anymore as the female half of the huldra population, but that doesn't mean there aren't plenty of old stories about them. They're not as shy about the holes in their backs, and unlike the females who usually target lone people in the forest, the males are sometimes smartass enough to ride into towns on a horse and lure their target into the wilderness.
Next to the huldrekarl is of course the good old nix. I'm sure there's some story in here about him losing his violin and trying to talk a pretty-but-slow huldrekarl into getting him a new one.
i'd actually been looking for more info on the male Huldra's for awhile, for a roleplaying game project of mine. now i know why my google searches didn't turn up much.. the collections of folklore that i had as a starting point used the term 'huldremen', not huldrekarl. seeing this, i did a quick search under the right term... still not much.
those same collections actually present the males as slightly different from their female counterparts., instead of having holes in their backs or tails, they were presented in an almost elfin fashion, with stories similar to the seelgie and unseelgie Fae of scotland and ireland. given that there were multiple scandinavan invasions and occupations of those areas, i wonder how much of the Fae stories stem from scandinavian folklore elements (almost certainly the changeling bit, i think), and how many of the scandianvian stories i'd been reading were the result of elements crossing over from the pre-contact stories of the Fae...
O
Ohhhh, question answered about the huldrekarl's back. Oo That's what I get for reading the posts backward.