Snap painting! Sounds like an amazingly fun amazingly messy activity! Can't wait to try it!
Harry Potter party game - Teams race to make a potion and winning team gets liquid luck made from sugar/eatable sparkles and water in a mini bottle necklace. Look up real Hogwarts potions and use real foods labeled with Hogwarts names. Make sure to include enough colored baking soda and vinegar to make a great reaction. In another one use dry ice and colored water. Such a cool reaction from the kids! Last one we did was a race to eat pop rocks that were in test tubes. So much fun!
Harry Potter Party Ideas: Potions Lesson! Dry ice+food coloring+ warm water=magic :)
Harry potter potions class. Bubbling Truth Serum. Ingredients were hippogriff saliva (water and a few drops of dish soap), crushed dragons bones (baking soda), and juice of jobberknoll feathers (vinegar). (add food coloring at the end)