Creatures, mythological or otherwise.

[iZolo]

Slender man.

[sabinati]

Slender man.

[JustasJ]

Mörksuggan, from Dalarna, Sweden (otherwise famous for the Dalecarlian horse).
I don't know if it actually does anything, I just like it. Wikipedia carries almost no information on it; only that "it was used to scare children, among other things".
I *think* that it might be something like a tomte, but I'm not sure.
I saw it translated as the Dark Sow once.

sounds like a Lithuanian "baubas"(a boogeyman hiding under a carpet) or "kaukas"(an evil spirit similar to troll) to me.

[kaka]

sounds like a Lithuanian "baubas"(a boogeyman hiding under a carpet) or "kaukas"(an evil spirit similar to troll) to me.

The *only* information I was able to find on it was this one thing my grandma (who was born and raised there) could tell me:
"Children were told by their parents not to go out at night or the Dark Sow would get them."