So...new problem. They're on their way back from the pet store with the crocodile (do they really sell those there?).

The bad news is - somehow....you're an asshole for saying no, and also an asshole for letting them have a pet crocodile. It's a lose lose - now you have new choices (they'll probably be lose-lose too)

Accomodate the crocodile - feed it special crocodile food and kiss it's crocodile ass and act like you wanted it all along.

or...

Get your own pet - and give it all your attention - knowing that ultimately, the crocodile is going to eat it (or call it stupid and ugly, then eat it).

Choose wisely....