Are you sure you aren't talking about the movie "Jaws"?
The worst most snapping turtles usually do is eat ducklings.
nope. I've had some experience with these beasts, and they are fearsome. don't try to get close to a live one - they attack suddenly and with more speed than you would think - they are highly mobile, especially int he water.
if you can find a dead one, look closely at the jaws - they will mark a hardened steel gaffe (I have one with said marks), and bite through most shoe material. They have bones atop their tails (the bigger ones) that evoke stegosaurus plates, and their shells have serrations to help them burrow into the muck and hide. if you step on one, he can reach back and bite you in the leg before you realize that that t'warnt a rock.