Um, hate to break it to you Brits, but Otters have two layers of insulating fur that repel water like a Darwinian poncho. Comparing a sun shower or perhaps a spattering of sprinkles to an Otters pocket would be acceptable. But to insinuate heavy precipitation is not only an insult to Otters, but to their god given slacks as well.

Which is not to say I'm opposed to mixing weather and idioms. But if you’re going to call a spade a spade, you damn well better be pointing at a card or a shovel. Otherwise, you’re all mouth and no trousers, and behavior such as that puts any man trying to prepare for a Monday at the end of his tether.