The Dreadful

After becoming trapped in the dark passageway that led down into Erebor from its secret entrance, the Dwarves of Thorin's company eventually braved the great chamber where Smaug had slept on his bed of gold. Finding the hall filled with the treasures of their people, they became distracted by the loot of the Dragon.

At this time Smaug had already been slain over Lake-town by Bard, but the Dwarves had no way of knowing this, and Bilbo Baggins was quick to remind them that, so far as they knew, Smaug the Dreadful (apparently a title coined by the Hobbit at that moment) could return at any time. Though they had gathered armour from among the hoard, Bilbo pointed out that it would do little against the Dreadful Dragon, and instead they began to make their way to the Front Gate and out of the darkness of the Lonely Mountain.