Shadow Mastiff (Basic Lore)

Shadow Mastiff (CR 12)
Pure Evil - Medium - Outsider
A shadow mastiff is a creature that looks like a large dog, except that its coat is deep, supernatural black. On a quick glance, a shadow mastiff may pass for an ordinary, if very large dog — 'man's best friend'. However, on closer examination, the horrendous evil lurking in this creature is obvious. Shadow mastiffs come from some dark place, some place outside this world, a shadowy place where the world is a twisted reflection of our own. This is the Plane of Shadows, where even the best things, like mankind's loyal companions, are twisted and evil. Shadow mastiffs exude terrible menace at the best of times, and when they make even the smallest of threatening gestures, fear grips the heart of even the most hardened souls.