I'm very tempted to either stitch together an OSR game with one of the popular expansion additions to 5e (most likely APPLE) or use Gorge World as a template, to have spell casting basically be the fatten/more inflated you are, the more potent your spellcasting is and the more spells you can cast, and do dungeon crawls. Being blown up vs your mobility and your size. Sure, you can cast that super powerful fireball, but you need to be pulled by a horse drawn wagon AND you constantly get stuck everywhere









