Thanks to Hollywood, when we think of serial killers, we normally picture a certain type: highly intelligent, manipulative, ferocious killers with little to no moral compass. Think Jeffrey Dahmer, John Wayne Gacy, David Berkowitz — even Hannibal Lecter. In other words, we tend to think of guys. Well, to be more specific, we tend to think of adult men. But what if those gruesome killers had started out when they were just kids? Who would be the world's youngest serial killers?

We've put together a list of the most gruesome serial murders committed by children. The eight kids in this slideshow are every bit as scary (and dangerous!) as the grown-up multiple murderers that we all know. But some of them are a little bit cuter — in a kind of creepy, sociopathic way.

Image: Murderpedia