Glaurung

Glaurung was a very powerful and cunning dragon, and he used his abilities to achieve his desired ends without resorting to direct physical violence. Glaurung was much more cunning than his contemporaries in the hierarchy of Morgoth. It was his nature to trick and deceive, and to spread lies and deceptions so cleverly that they could not be discovered until it was too late. In this manner, he accomplished much more damage than he could have with brute force, and caused the destruction of the Elven stronghold of Nargothrond and the death of mankind’s greatest hero to date, Turin Turambar.