Jellyfish in a Bottle - How cute! A pet that doesn't need feeding. However, I am considering using glitter in the water and glue of some kind inside the cap just to make sure my kids can't get it open. How Finding Nemo is that?! "And he will be my Squishy..."
plastic bottle + vegetable oil (half fill the bottle) + water (fill the rest of the bottle + 10 drops food coloring + alka-seltzer (broken into pieces, placed 1 at a time into the bottle) = lava bottle