Frogs in Fiction #9 - The Scorpion and the Frog

Has anyone seen the movie "Drive"?

An animal fable about the immutability of one's nature. The story goes that a scorpion asked a frog for a ride across a river. The frog, of course, is hesitant and says he's worried that the scorpion will sting him. The scorpion retorts that if he did that while the frog is swimming, he'd drown as well. The frog believes that makes sense, and agrees to help. Halfway through their journey though, the scorpion stings the frog. When asked why, the scorpion replies that he couldn't help it, and that it was in his nature. (Good thing humans would never do that, what with free will and such)