Black Panther

Also called the shadow cat, the black panther is made of shadowstuff, not flesh. Casual observers take it for an ordinary black leopard of the kind found in dark jungle forests, but it is leaner, built more like a cheetah, with pearl-gray fangs and claws and dark eyes that flicker like black flame. It cannot speak but readily understands humanoid languages.

It stalks and pounces like other great cats, clawing twice for 1d3 each and biting for 1d8. If both front claws hit, it also rakes with its hind claws for 1d3 apiece. It can leap 20 feet straight up or 50 feet forward or back.

Except in the brightest light it is 80% undetectable, and when still in anything dimmer than torchlight it counts as invisible. It moves without a sound, imposes -4 on foes' surprise rolls, and is never surprised itself. Not truly alive, it ignores magic and effects that work on living things, along with suffocation, disease and poison.

At will and instantly, even after attacking, it can collapse into a pool of inky liquid darkness, though it cannot do both in one round. As a puddle it is untouchable by any attack or spell but cannot enter the area of a light spell. The pool glides at movement 36 across floors, walls, ceilings or water and seeps through hairline cracks. Its favorite trick is strike, melt, slide behind the target and re-form to attack next round; it also uses the form to flee when badly hurt. Unlike a vampire it does not change automatically at 0 hit points, and dies normally.

Black panthers probably come from the plane of shadow, though how they reached the misty dread realm is unclear; perhaps through the hidden shadow realm with other creatures of darkness. They are common in that fey land, possibly because they like its gloom, and elsewhere haunt dark forests rich in game and intelligent prey, especially one jungle-shadowed domain.

Vain, fussy, sly and pleasure-loving, they are wholly evil yet enjoy play and attention. Like tigers they live alone except for mothers with cubs, and two wild panthers fight unless ready to mate, though captive groups merely compete for their master's praise. Vampires, weretigers, feline shapechangers and the shadow fey keep them as guards and companions. Pampered, groomed, well-fed and respected, they are loyal and affectionate; neglected, they turn vicious and vengeful.

Supernatural or not, they live as great cats do, preying mainly on mammals but by nature preferring intelligent victims. Evil beings covet the cubs, and wizards, especially shadow mages, pay well for a carcass.