Outscamming a scaly schemer

"How do you make a dragon do something he doesn't want to?

Brute force is obviously out. Bribery is out - he's annoyingly, well, content isn't exactly the word, but certainly stuck in his little rut: we don't know of anything he wants. Blackmail is problematic too, since (contrary to all draconic tradition) he does not seem to care for reputation.

Manipulation is going to be difficult because he is neither stupid nor naïve. But a direct request would be turned down and would put him on guard.

How do you deceive a deceiver into playing a role he doesn't think he wants to play?"