This document describes two pre-historic animals - T-Rex and lizards. T-Rex were large, meat-eating dinosaurs that were the most fearsome with over 500 teeth and could eat humans in one bite. Lizards, while much smaller at 5-6 inches, were also present in pre-historic times and continue to survive today, though they can die if their tails are cut off more than 15 times as they rely on their tails to flee from predators.