Make some rice crispy treats or similar marshmallow cereal treat then tell your students to make an animal using the rice crispies. When you're done, check this out.
First of all, he was very impatient and grabbed hold of the pile of treat while it was still far too warm to do anything but stick to his hands.
After cleaning off his hands with his teeth, he tried again, this time using two spreaders as tools.
He made a triceratops. (You can't tell from this angle, but it actually does have three horns.)
Before I could get a better picture, he said, "I'm a tyrannosaurus rex, and I'm eating this triceratops!" And that was the end of that.