“Never heard that one. Tell it to us!”
If you are serious, (as best as I can remember)...
A scorpion approaches a river bank unable to cross. He sees a frog and asks the frog if he will allow him to ride on his back in order to cross the river. The frog sais, “if I allow you to ride on my back, how do I know you will not sting me?” The scorpion replies, “If I sting you, then I will drown too”. The frog agrees to take the scorpion across the river. About half way across the river, the scorpion stings the frog. As the frog is dying and sinking into the river he asks the scorpion, “Why have you done this, now we are both doomed”. The scorpion replies, “It is my nature”.
I’ve heard that story but using different animals.