Hieroglyphics of Horapollo, tr. Alexander Turner Cory, , at sacred-texts.com
To symbolize an unjust and ungrateful man, they depict TWO CLAWS OF AN HIPPOPOTAMUS TURNED DOWNWARDS.
[paragraph continues] For this animal when arrived at its prime of life contends in fight against his father, to try which is the stronger of the two, and should the father give way he assigns him a place of residence, permitting him to live, and consorts himself with his own mother; but if his father should not permit him to hold intercourse with his mother, he kills him, being the stronger and more vigorous of the two. And they make use of the lowest parts of the hippopotamus, the two claws, that men seeing this, and understanding the story of it, may be more inclined to kindness.
II. Has the body of an hippopotamus.