[thaumasiotes]

According to http://en.wikipedia.org/wiki/The_Frog_and_the_Mouse , you can find each moral in Aesop, with the frog and the mouse teaching that evil destroys itself and the farmer and the viper teaching that you're a fool to hope for anything but evil treatment from evil. Presumably, you'd target the first lesson at people you wanted to shape up, and the second one at the excessively giving.

On a different note, http://en.wikipedia.org/wiki/The_Scorpion_and_the_Frog is only listed in WP's "apocryphal" subcategory of Aesop's fables, dated to 1954. What's it doing on "www.aesopfables.com"?