One clarification: somebody above was under the impression that a cougar/mountain lion/etc is some sort of "hard target".
Not so. Anything useful in defending against human assailants is quite effective agaist the kitties
. Many have been taken with .22 rifles...a .38snubbie with good 158+P LSWCHPs is not a serious disadvantage although more is of course better.
They pretty much never hit 200lbs in North America, usually less than 150, and are not particularly determined assailants if you fight back. One guy in California saw one dragging off his small child, and beat it over the head with a rock, driving it off and saving his kid.
When they do take down an adult human, it's generally from behind, either by stealth or somebody was stupid enough to run. DO NOT run from a megakittie. Pull a knife if you have to, grab a rock or a club, stand your ground.
Or shoot the dang thing
. Empty an entire .22LR handgun into it if you have to, you WILL get results.