Let's play a game - you crawl into your bed at night and just get a feeling that something is off. So you grab a flashlight and look under your bed (or make your significant other do it). Quick! What is the one thing you really, really hope you don't see? Is it an axe murderer? Someone else's used protection? A sinkhole? The worst things to find under your bed could be realistic - like dust bunnies (what are the odds that those aren't under your bed?) or they could be totally creepy like a rogue Furby. What do you hope to never see?
Some of the suggestions on this list are strange things that were found under beds in real life. Some are things under your bed that could probably only exist in your imagination. Have fun with it and vote up the things that would really give you the heebie jeebies.