Castle Freak is a 1995 film directed by Stuart Gordon, roughly based upon the short-story The Outsider by H. P. Lovecraft (it has elements of splatter/slasher and even a nod to Creature Features).

Plot

After inheriting a 12th century castle, John Reilly and his family travel to Italy where they discover that this new inheritance may not be such a blessing after all. Unbenownst to John and his family, the duchess' son still lives in the dungeons of the castle. He breaks free, and tries to harm John and his family, killing the housekeeper and a prostitute in the process. John must now save himself and his family from this castle's unknown inhabitant before the "castle freak" has his way with them.