Three Hundred Æsop's Fables/The Crab and the Fox
THE CRAB AND THE FOX.
A Crab, forsaking the sea-shore, chose a neighbouring green meadow as its feeding ground. A Fox came across him, and being very much famished ate him up. Just as he was on the point of being eaten he said "I well deserve my fate; for what business had I on the land, when by my nature and habits I am only adapted for the sea?"
Contentment with our lot is an element of happiness.