On Mim's birthday, I snuck a garbage bag full of pink balloons into her room. When she ducked out to pick up some dinner, I taped paper ears and ribbon tails to them, drew noses and feet on them, and set them free across the ceiling.

The look on her face when she got tangled in them as she entered the room was priceless :)

(click to see the original Pig Balloons drawing)