When is Smaug first introduced in The Hobbit?

Answer 1

Smaug's name is first mentioned in Chapter One: "An Unexpected Party" in passing by Thorin:

"Old Smaug has lived there long enough now to find out anything there is to know about those caves."1

We learn about Smaug and the dwarves' story later on, as Thorin explains what 13 dwarves and one wizard are doing in Bilbo Baggin's house:

"There was a most specially greedy, strong and wicked worm called Smaug...."2

We finally see Smaug himself quite a few chapters later in Chapter Twelve: "Inside Information."

"There he lay, a vast red-golden dragon, fast asleep; a thrumming came from his jaws and nostrils, and wisps of smoke, but his fires were low in slumber. Beneath him, under all his limbs and his huge coiled tail, and about him on all sides stretching away across the unseen floors, lay countless piles of precious things, gold wrought and unwrought, gems and jewels, and silver stained red-stained in the ruddy light."3

1. Ballantine Books paperback edition, p. 20
   
2. Ballantine Books paperback edition, p. 23-24
   
3. Ballantine Books paperback edition, p. 215