Drains are mysterious things. When we were younger, we assumed anything flushed down the toilet was gone forever. The pipes may as well have been portals to the underworld, where things go never to be seen again. But you grow up and realize, that sometimes, things flushed away resurfaces. 

And when they do, it's always at the worst time. Most notably, when you're at your most vulnerable, with your pants down, exposed to the underworld rejects. Snakes, bats, bugs, hands, and slugs, are just a few things that have emerged from the dark, watery depths.