The toothy mouth might be a problem. I would be poorly suited for consuming the small particulate items that dominate the typical chickens diet. Larger fare would have to adopted and for around here (central Missouri) if such a critter were to free range, diet would likely be optimal if based on same things a roadrunner or wild turkey eats. Problem is for most vertebrate prey a roadrunner consumes, the unmodified parts of bird would be too slow to pursue. Critter would likely have to dump balance of flight gear (breast muscle).