The Steeds of the Dead

The ground is littered with dead, man and horse, all torn and dead. Arrows piece armor, and limbs have been hacked from bodies. There is a lake of blood here, it is all red, the blood of men and their horses, drug down into death with them. This place is a charnel house, it is a place of desperation and murder, nothing good will come from this soil again. The bodies should be gathered and consecrated to the gods and entombed in the earth least the dead rise in their anger and restlessness.

Full Description
The Steeds of the Dead are rare ghosts, the spirits of horses slain. Like men, few horses ever rise as ghosts, most of these noble beasts are immune to the bitterness and vitriol that bind the restless dead to the world of the living. But there are some horses, some who were great of heart and strong of head, the sort of animals that are ridden only by kings, warlords, and great and mighty warriors. These animals take something from their masters, something of their tenacity and desire to continue even after their life has been snuffed.

A steed of the dead appears as a jet black horse, no matter it's color in life. The mane and tail are unnaturally long, but unlike human ghosts who seem immune to even the strongest winds, the hair of a ghost horse is constantly blowing in a great wind, even if there is not a breath of wind. Their eyes are luminous, golden orbs glowing in their black faces, many have been unnerved by the sheer display of supernatural power that these spectres generate in their appearances.

We were half-wat across the Candleland Fields when it appeared. The last time I saw that horse, we had pulled it's rider off, slit his throat and broke the horse's legs so they could watch each other die. We ate good on his gold coins, left both of them to rot in a gorge where no one would find them. I felt my heart grow still, my blood cooling with fear. The old man was nowhere to be seen, but that damned horse was coming towards us. We spurred our ponies but it came on relentless as the hosts of of hell itself. When it got close enough to hear it's snorting breath our horses just quit running, just gave up. Timal was thrown and I'll be damned if my own mare just laid down on the ground. I still remember the sound of Timal's ribs crushing, that horse caught him on the ground with both hooves. He made a bubbly sound and died. I wept as the black horse hunted and killed each of us one by one. It was only a moment from killing me when the sun broke the horizon. It looked at me, looked into me. I'll not step another foot out there on the Candlelands, not for the Queen's panties or all the gold in the Kingdom.

Additional Information
The Steeds of the Dead are relentless ghosts, able to move at greater speed in death than in life. They need no water or food to continue. As semi-incorporeal undead, they cannot be harmed by mundane weapons or fire. Magical weapons can harm their essence, as does magic itself. Aside from magical barriers, a steed of the dead can pass through almost any barrier. Those that somehow defy their ability to pass through solid matter are easily jumped or otherwise circumvented. A steed of the dead can shift from the land of the living to the land of the dead to bypass an obstacle, such as a prepared defence, and then return to the land of the living.

The steeds of the dead can also command living horses in a limited fashion. Direct commands are not given, but if a mortal horse comes in earshot of a dead one, they will cease running. A mortal horse is never in any danger from a dead horse, as they bear their living ilk no ill will. Quite the opposite, most will protect mortal horses from humans. Such bespelled horses will do what they can to rid themselves of riders, from bucking and kicking to simply rolling on the ground.

These dead creatures cannot bear the light of the sun, so they hunt only from sunset to sunrise and anyone who can evade one for the duration of a night has a reprieve to escape the ghost's territory.

Arise, mighty steed, arise Lohgren, steed of the fallen King, rise and bear me as you once bore the King of Kings!
Adamant Spectre ~ Necromancer

There were a hundred of them, I could hear the gnolls slavering and snorting. They had my trail, I was blooded and leaving a trail that even a goblin snotling could follow. I thought my death was soon come, but I had my sword out. I would die with my boots on, my blade wet with their blood. It was then that I heard it coming, a crushing of the brush from the other direction and I saw him. He was a beast of a horse, 18 hands at the least, his mane and tail were night winds and his eyes shown like topaz in the moonlight. I had a fistful of his mane and I was on his back, I didn't know this horse, but I know a warhorse when I see one. He reared, but somehow I stayed planted bareback on him. He called out to the night sky and I could hear the gnolls panicking and confused. I laughed as this strange horse bore me away from death, I would deliver my message and in a sennight the King's company would scour the gnolls from the Candlelands.

Memoirs of Jeddit, Adventurer-Upon-Return

Summoning and Mastery
The Steeds of the Dead can be summoned and ridden. Summoning one is no different than summoning a normal ghost, the offerings are little cheaper though, usually nothing more than a few smoldering stalks of hay or dried alfalfa. Once the ghostly horse is appeared, things are more difficult. As creatures of power and charisma in life, their ghosts are no less for their deaths. Wards to hold a ghost horse must be larger and stronger than those to hold a human ghost. A suitably intelligent necromancer can ensorcel a steed of the dead to serve as his mount at night. This is the more common method of controlling dead horses.

In times of great need, a steed of the dead can appear to a hero in need. For the duration of a night, the dead horse will respond to the hero as if it were a live horse, to the point of bleeding if it is wounded. It will not accept food, water, or being tied though. These steeds of the dead are subject to the same limitations of only appearing at night, and have the same immunities to mundane weapons, even if their flesh shows an injury.

Plot Hooks
Clear the Road - A Steed of the Dead has appeared, likely along with a handful of other malignant ghosts on a secondary trade road. The spectres need to be dealt with quickly so that trade can resume. The PCs have been contracted to find and destroy the ghosts as quickly as possible. The snag comes that the local lord very well knows the source of the ghosts, as he and some of his men committed the deed. Rather than reveal his violent hobby, and involve the faith, he would rather hire a few adventurers who aren't keen on asking questions.

The Kingdom may not be lost... - Suitable for a solo adventure, a hero has captured the Dingus, or disabled the villain's plan, but he must now make a quick escape or face death or defeat. The PC is found by one of these night black steeds, does he dare ride? Or does he trust more in his own feet?

The Silent Watcher - The steed of the dead has watched over a certain patch of land for generations, it is a safe place to keep horses and livestock, and the hellion horse has offered no offence to the village folk. They have gotten used to each other, and while the ghost of the stallion watches the herds and tramples the occasional horse thief, the villagers have adopted it as a village mascot. The local tavern has a black horse head on it's board, the brewer burns a black horse image on his beer barrels and so on. The villagers are quietly protective of their ghost, and will not take kindly to PCs who want to capture or destroy the entity.