All I can remember of this movie is: There is a party going on in this beautiful room. There are lots of people dancing. The women are wearing big dresses and the men are wearing tuxes. There is this room down the hall that you are never to enter/open. Some of the kids open this room. While all the dancing is going on, the room is opened and the "thing" which happens to be a big bubbly chocolate looking mess starts to creep out. That is all I can remember. I watched it in the 90's but not since then.

Little Nemo: Adventures in Slumberland (http://www.imdb.com/title/tt0104740/)

Quinn F- Thank you for responding. I thought it was that movie also but when I watched it, I didn't see the part of the movie I am looking for.

Just to be sure, check out this clip.
YouTube - Little Nemo part 9 (http://www.youtube.com/watch?v=P_t94JYvdGc&feature=related)

WOW! That is amazing! You were right! Thank you!

Glad to help.