Stegosaurus

The huge Stegosaurus with its very sharp spiny plates is usually a peaceful animal in the valley of Eodon. Stay out of its way, and it won't have any interest in you. However, should you dare to make it angry, it will show of what matter it is made of, before shredding you to confetti. This is why even the Tyrannosaurus avoids it when possible.

Therefore it is better to not anger it.