Here's a method that might or might not work. I took the animation I wanted (in this case, Wario's bite), extracted it, and put it on the .pac file with the model I wanted (in this case, FitKirbyMario00.pac.) Then I renamed it to FitKirbyWario00.pac so he would get that hat when he inhaled Wario.
The result can be seen
here courtesy of MnSG.