What always weirded me out was the obsidian orbs they had to eat. 1d20 inches in diameter. A foot and a half is fine for a full 100' long dragon, but... the lack of detail on when you determined the size of your next orb caused some concern.

Although I suppose there's nothing stopping some enlarge/shrink hijinks going on. Still, two or three high rolls when you're just starting down the dragony path... Beware of anitmagic fields or suffer a tummy ache you'll need regeneration to get over.