The Dog and the Oyster.
Reading edition
A Dog, used to eating eggs, saw an Oyster, and opening his mouth to its widest extent, swallowed it down with the utmost relish, supposing it to be an egg. Soon afterwards suffering great pain in his stomach, he said: "I deserve all this torment, for my folly in thinking that everything round must be an egg."
Who acts in haste repents at leisure.