To make this cool prank, you'll need: a balloon, a small toy dinosaur and some food colouring
Put the dinosaur into a balloon. You might need to stretch the balloon over it, but take your time. Make sure you don't put a hole in the balloon because that is going to make a mess!
Pour a few drops of food colouring into the balloon. then fill it with enough water to surround the dinosaur. Tie the balloon shut and stick it in the freezer overnight.
In the morning, peel the balloon away from the frozen liquid - this is your frozen dinosaur egg. Epic, isn't it? YOu can keep it in the freezer until you're ready to play your prank.
Now all you have to do is pretend you found the frozen dinosaur egg. When you tell people you think it's a dinosaur egg, they won't believe you - but when it thaws out to reveal a baby dinosaur, they'll be totally freaked out!
And here he comes - forget palaeontolgy - this is LOL-aeontology!