Freeze water in a surgical hand glove to make a creepy ice cube for Halloween Punch! This would be cool, as long as the creepy ice cube doesn't smell like a glove.
Spinning Spirits: Spinning ghosts: Hung from the ceiling, these friendly paper ghosts will swirl, sway, and spook all night long ;
Chocolate pudding "Pumpkins" made from oranges. More genius ideas this way.
Diy nebula in a bottle!