A single snowy sabre cat isn't a "mob".
Actually, in gaming terms, a "mob" is anything that is an enemy of some sort-- singular or plural. People need to stop being "debbie downers" and learn that no amount of negativity on forums is needed.
On the actual topic of the post, however, you are probably getting owned due to the fact of poor planning. I play on master difficulty and strategize fairly close to every second i play the game. It is a difficult game, to some, and to the some that it is difficult, it requires actual intensive play. Hit the sabre cat a few times, then pause and heal with potions, rinse repeat. If that doesnt work, throw a shout in there a few times. when the cat goes to strike, back away, or block. The game is not to hard nor is it too easy; Regardless, if it is, change the difficulty. Don't worry about the label of difficulty, worry about how difficult it actually is.