I tried breeding a fat chocobo - or chocobese, by giving it plenty of fatty food, VanaTV access and no walks. Results were... disappointing. Having your stash of mithkabobs regurgitated by a chocobese tends to diminish their palpability.. not to mention the smell of your armor. Being shunned by your fellow adventurers is bad enough, but even marlboros make themselves scarce when you get within 100 yalms...