Who needs a guard dog when you have a cat?!
Cat vs. alligator: http://youtu.be/k05PX_N5KKk
Two cats vs. two alligators: http://youtu.be/5sAF8gMN9c0
Cat vs. snake: http://youtu.be/eEZMctgaXNQ
Cat vs. bear: http://youtu.be/57VbE0J9niw
And...
Cleveland, Texas - man gets into knife fight with cat, gets airlifted to hospital: http://www.neogaf.com/forum/showthread.php?t=429797 (article only). I can't find the news video, but the fellow was very good size and very heavily sedated with big stitched wounds. The man will never live it down: Whatever you say about the outcome, the guy got his ass kicked by a cat!
Lesson here (from one of the comments): "You don't bring a knife to a cat fight."
BONUS: Cat vs. cat, with dog the winner: http://youtu.be/H4uQ9f8bH-w
