Diabolus

Diaboli are about human size, with muscular mauve or lilac bodies, pig-like hooves and hands that look human apart from having three fingers and a thumb. Their eyes have slit pupils like a reptile's, most have large noses, and two small vestigial horns poke from their heads. A tail a bit longer than their legs trails behind them. Their long forked tongues sharpen their smell and hearing and let them sense heat.

There are at least three subraces, told apart by hair: the bare diabolus has none, the common diabolus has a human head of hair and a beard, and the hirsute diabolus also carries a thick goatlike coat of curls on its lower body. All speak their own language and can also signal with intricate twirls and poses of the tail.

A diabolus has almost exactly human abilities and can take up any human class with the same limits and benefits. It adds two natural attacks: a bite for 1d6 and a tail sting for 1d4 that injects a mild venom, paralyzing for 1d6 rounds anyone who fails a save vs. poison. Diaboli are immune to their own venom.

They use most weapons but favor the trident, which also serves as a way to move. Planting tail and trident in turn, a diabolus can cartwheel at double its normal movement rate. This takes full concentration, tires it like running and lasts at most 30 rounds. Diaboli cannot actually run, but cartwheeling lets them charge with the usual bonuses and penalties.

Natural agility gives them base AC 9 rather than a human's 10, and in any armor they are 1 point better than a human wearing the same.

Strangest of all, Prime Material magic does not affect them, and their magic does not affect Prime natives. A human wizard and a diabolus wizard could fling fireballs at each other all day without a scratch. Indirect tricks still work, such as using telekinesis to drop a rock on a diabolus. Diaboli are affected normally by spells from their own kind and from other natives of their home demiplane, such as brain collectors, feyrs, nagpas and maelephants.

Diaboli come from a mysterious realm called the nightmare demiplane. Its inhabitants look nightmarish to humans and their kin, though most diaboli are kindly and good-humored, and they in turn see humans and demihumans as living nightmares. A few centuries ago adventurous diaboli found gates to other planes, and many have since explored and settled other worlds, keeping away from humans and most ordinary creatures, which disgust them.

Most believe chaos is the natural order of things and happily share its joys with anyone willing, without pressing the idea on others. They have no rulers or formal institutions, yet custom and a strong sense of fair play keep their trade and communities running. They shun violence and hold firmly to a code of non-interference; their warriors fight to protect their homes or for adventure, rarely for the love of killing. Their technology is primitive, but their art, philosophy, generosity and tolerance often surpass humanity's.

Humans and diaboli usually find each other repulsive, though seasoned adventurers, generally those of higher level, often learn to look past it.