Smaug stopped where he stood reared on his back legs, staring at the shimmering gold in awe. Even though he had the entire hoarde of Erebor that he had kept to himself for all these years, like all dragons he was weak to anything gold or treasure, and for a moment he forgot that he had been about to try and kill the dwarves.

He hissed in surprise as suddenly a bubble appeared in the figure's face, and the gold statue collapsed on top of the dragon. 
"Argh!!" Smaug cried out, flailing frantically underneath the swirling sea of molten gold. The dwarves looked on in surprise and were silent as they wondered whether the plan had worked, when the gold stopped rippling and they could no longer hear the dragon's cries. But seconds later, he burst out of the molten gold, which sizzled against his scales as he yelled in pain.
"Revenge?! Revenge? I'll show you revenge!!" the dragon bellowed, crashing through what had once been the front door of the kingdom.