My friend george was squirrel hunting with his young nephew and a cougar snuck up from behind just as the cougar was leaping at george, some reason george turned around at that moment george emptied his 10 round magazine from his ruger 10-22 killing the cougar in mid flight, the cat landed just a few inches from his feet.
This was in northern arkansas around there they recommend hunting in pairs just for that reason of possibly getting attacked by a cougar.