"Fastelavn" is a Danish tradition where kids dress up and go from house to house singing a song and get candy, so it's very similar to Halloween. "Fastelavn" stems from an old Christian tradition, where they 7 weeks before Easter celebrates Shrovetide ("Fastelavn"). In the Christian tradition "Fastelavn" marks the start of 40 days without meat, though I doubt that is the reason why most people celebrates "fastelavn" today.
At most "fastelavn" parties kids will hit a wooden barrel with at stick (very much like a pinata), the one who gets the barrel destroyed ends up being "Cat King". The game is called hitting the cat out of the barrel, and until the 1830's they put a real cat inside the barrel, because they believe that a town could be spared of the plague is a black cat were killed. Today there is only candy in the barrel, and sometimes the barrel is decorated with a painting of a black cat. I guess out cat Gilbert should be glad that tradition has stopped, otherwise he should be hiding most of the month of February.
Jonas and his friends celebrated Fastelavn with the other kids from the daycare. He was dressed as a spider, since I figured it would be the best costume for him since he probably would be too impressed with a big costume. So he was dressed in black, and I had put some velcro on his back and some velcro on some stuffed socks. So he suddenly had 8 "legs" at least if you count his own arms and legs:) I had knitted a hat for him, and put eyes on it, though he wasn't too fond of the hat:)