If Godzilla trained with Mackie Shilstone to properly shed the weight. Who wins? Would Godzilla's sort arms hurt his chances. Would Floyd shoulder roll away from his fire breathing.
Mayweather would win. Godzilla would be severely weight drained. Besides, Floyd would sidestep the atomic breath, avoid the short arm lunges, use the ring to avoid the teeth and give the pre-historic lizard a boxing lesson. Floyd is no Mothra and he would have knocked out MUTO in 3 rounds.