[andrewas]

OK, first remove all the frost slamanders - you want to be able to concentrate on the big guy. Now, romove all electricity-based attacks from your spell books, replace tham with spells that wont heal him instead. Run away from him and rest. It *is* possible. Then do the 3 LR and pound into oblivion.

ALternatively you could shapechange a spellcaster into a Illithid (via the level 9 spell "shapechange") then Time Stop and suck out his brain while hes in human form - he never gets a chance to become a dragon, although you still get the scales. This way is Cheese however.