The long and short of it: a kingdom [i]really[/i] wants this dragon dealt with. It's been there longer than the kingdom has, but... it is very, very firmly [i]stuck[/i]. Still, it's sitting on a hoard of over a thousand years' treasure.
Being a colossal red dragon trapped in an AMF, the party has no chance of reasonably killing it.
Instead, you end up doing jobs for the thing. Because, really, after over a thousand years stuck in a cave, it's hard to still be Chaotic Evil.
 
Character Creation:
32 Point-Buy
Level 3
Full WBL
All official sources allowed (homebrew/non-WotC [b]IF APPROVED[/b])
Nothing with LA. Please.
Don't take things too seriously.
Unless someone REALLY wants a very AoO and (in general) space-concerned character, I'm not bothering with maps. Even then, you have to deal with hex grids because circles suck.
Excessive optimisation will be rejected on those grounds alone.