Kids will have fun exercising patience and watching as this unicorn progresses. Get a clear bucket of water or a fish bowl so your children can watch this egg hatch over 24 to 48 hours. Make sure the water is room temperature. Even after the egg hatches and the shell breaks, the unicorn will continue to grow. Feed it more water if you have to, just make sure it stays submerged so it can continue to grow over the next 5 to 8 days.