I nabbed this from http://rpg-directory.com/threads/another-sandbox-fantasy-idea.40921/
Terror has gripped Durandal like never before. For the past year, the land has changed from a relatively normal place to a land filled with magical and dangerous creatures. The lands of Durandel have been swarmed by all manners of creatures that prey on citizens of all nations. Creatures like the Gorgos, Imps, Harpies, Succubi and Incubi, the undead, and many more move about the country side killing and ravaging everything in their wake. The entire known world is caught under the terror of the tales of these creatures. There seems to be no ending to the stream of these new beings causing the rich and poor to be caught in fear.
There is no known source of the apparition of these creatures, only rumors exist. They are numerous, from the end of the world to even new lands being found and people shipping these creatures here. A rumor that seems to stand out is one of a rogue wizard trying to create new life through magic. It is said that these creatures are his failed experiments he wrought upon the land. One of his creations that stand out in the tales is the Black Dogs. Giant undead dogs with red eyes the size of a cow. Whenever the dog appears, someone is taken to never be seen again.