[HerenIstarion]

Bilbo: I tell you!
Gandalf: Hm-m?
Bilbo: Come on, Gandalf, I tell you the oliphaunt Gollum promised to give me if I won in the riddle game had a tusk this long! Or maybe even longer! He said his granny gave him that oliphaunt!
Gandalf (thinking): He thinks I'll buy it, like If I don't know what Gollum may have had on his lake! He thinks I'm slow or what?. Heh, I know it was a boar, not an oliphaunt!