Look, just say what makes you the biggest and you'll get ALL of it. ...though then the city is doomed regardless from expanding dragon.

Ha! That's a good point. Honestly, a good bit of energy easily does the trick for a fire dragon. Really lets those muscles swell and bulk out under the scales so a big guy can surge to a proper size. Though I'm also grateful to those same cities for being so good at letting me have plenty more energy when I visit like that. They really make sure I loom over the place proper.