The world is rife with stories related to spirits and the spirit world. From the appearance of unicorns and tainted animals to the belief that Devout's show up to lead armies to battles for the most faithful, its accepted that there is a world of spirit and spiritual creatures out there. Even if no one is hauling in a dragon corpse, the possibility that they are out their remains a belief.
There are no unicorns or werewolves that exist, with their own culture and society however. What is believed is that any such sighting of supernatural proportions is probably the work of the Visitante. These are spirits of faith that interact with the world, influencing the world on behalf of the other world. Depending on one's personal faith the names and circumstance of belief might change but the Visitante are a universal force in the mortal world.
In the times that the spirit of a Devout may have been witnessed, or a unicorn or even giant eagles, the belief is that the Bene Visitante are at work and the individual is blessed in such a manner to have received the aid of the Visitante. The Bene Visitante are believed to have a stronger influence in the world of mortals and thus are rarely seen themselves but more that their handy work is witnessed by mortals first hand.
Opposed to these Bene Visitante are the Cattivo Visitante, evil spirits. it is unknown if they work for a singular dark entity or numerous dark other world princes and kings, but the Cattivo Visitante are benign spirits in the world. Unlike the Bene Visitante, they do not so readily interact with the world. Instead, on certain days when dark magic is rumored to be at its highest, male and female Visitante lay with mortals. It is the offspring of these unions, the Brutta, that are believed to be the main influence in the world.
Ogres/trolls/hobgoblins, any other such name given to them, these ugly spirits are corporeal and live mortal lives. Protected by their mortal parents, for whatever deal was made with the Cattivo, the Brutta can harness the darkness. While the shining examples of tainted creatures of the Bene Visitante are hard to mistake, the taint of the Brutta on such creatures is sublime. Taking time to build up true a true taint to affect the world, they slowly scheme and plot against the Bene Visitante.
These are rare at best, not everyday things that occur.