According to my Swedish Father, Luuckintuse was a creature who lived under bridges and came out to "get" bad children. Over the years it became a threat word for anyone in the family, adults too, who misbehaved, lost their temper, swore. We think a Luuckintuse was something like a "Troll" - never sure. They would come out from under bridges, grab bad children, and only let them loose if church bells rang. (I bet I have that description messed up!)
This is a current, finished project of DH. I made the sail, which developed some crookedness after I broke one of the lines a few minutes ago, while cleaning off the table, so we could take photos!