The Hitchhiker's Guide to the Galaxy by Douglas Adams

Prostetnic Vogon Jeltz was not a pleasant sight, even for other Vogons. His highly domed nose rose high above a small piggy forehead. His dark green rubbery skin was thick enough for him to play the game of Vogon Civil Service politics, and play it well, and waterproof enough for him to survive indefinitely at sea depths of down to a thousand feet with no ill effects.

Not that he ever went swimming of course. His busy schedule would not allow it. He was the way he was because billions of years ago when the Vogons had first crawled out of the sluggish primeval seas of Vogsphere, and had lain panting and heaving on the planet's virgin shores. when the first rays of the bright young Vogsol sun had shone across them that morning, it was as if the forces of evolution had simply given up on them there and then, had turned aside in disgust and written them off as an ugly and unfortunate mistake. They never evolved again: they should never have survived.