What actually happened here was the fat cat's only defensive maneuver in this scenario. The much more fit cat would of had him set up for a devastating Omae wa mou shindeiru combo but the slower heavier cat had a plan for this situation. By using the gravitational field surrounding his much larger body he pulled the fitter cat over him making him look foolish and unable to attack again since when a cat messes up an attack they have to pretend like it didn't happen and move to the next room.