True Hybrids

People say that hybrids dont exsist. I on the other hand disagree. Humans thing foolishly. If werewolves, vampires and other supernatural beings dont exsist, how did they come about. No everthing is made up from human minds. They could be real but never seen again. I know about hybrids (werewolf and vampire) alot. I know a true spell that works for children between 12 and 17, although it is a long periodic spell. That is why I determined age.