Because chainsaws are cliche..

Behold my implement of terror and carnage: the Anklebiter! Also referred to is as a BarbieWacker and a couple other names as well (which I cant remember off the top of my head.) Its what it looks like: a mating between a gas-powered weedwacker and a 10 or 12 inch circular sawblade. Didnt build it, but I got to wield it as I chased the sterotypical "prom-queen in the ugly dress" for the movie. I had way too much fun doing that.

As far as practicality, this is pretty weak. Maybe one horsepower & it tended to bog down when cutting through anything (used it to cut through a cheap door.) But, it could do some serious damage to tendons & muscles.