The Horned Reaper is a creature of significant power in Bullfrog’s Dungeon Keeper games. He has two distinct incarnations. One as a very powerful, but ordinary creature, and another as a unkillable, killing machine that comes from another hellish dimension. The former is usually known as a Horned Reaper, the latter is known as Horny.
The original Dungeon Keeper introduced the Horned Reaper as a special bonus creature, he could be summoned by sacrificing certain creatures in the temple. You could, in fact, collect multiple reapers, although this was not advised since they had a tendency to fight with creatures on your own side. Hugely powerful, these beasts would cut most attacking forces to shreds, but they could be overpowered if you were unlucky. (A freeze spell could conceivably cause a quick death here.)
Dungeon Keeper 2 took the Reaper to a whole knew level. Now, instead of being in essence a particularly powerful creature he became something entirely different. Although he still manifested as a creature on your side there was no way to attract and train him. To recruit him you must collect the four pieces of the Horny Talisman. This ancient artefact would allow you to summon the immense beast. Once summoned Horny could not be killed or wounded, and could slice through enemy creatures with one blow of his gigantic scythe. Unfortunately he was a huge drain on your mana supplies, (this is the currency of magic in the game). This lead to him disappearing when you ran out.
Both Horned Reaper versions look roughly the same. Huge red beasts with four large horns, one on either side of their foreheads and one on either sides of their chins. They had cloven hooves and wore metal armour in various places; They look very much like an incarnation of Satan. Interestingly their weapon of choice is the scythe. Although they seem to be able to get along extremely well with this ungainly weapon, it is difficult to imagine how it could be a versatile as, say, a staff or a sword.>{?
Whilst googleing I came across an unofficial legend of the origins of the Horned Reaper. This is not endorsed by the makers of the game but still is an interesting story (the following is not a copy and paste, it is a re-telling of a legend, enhanced for your enjoyment). It was discovered when a Warlock was looking through a library searching for information on the turncoat spell. He came across a book, “Servants of the Dark Gods, History of the Reapers.” Clearly this interested the Warlock and he began reading.
“Long ago the Dark Gods commanded a huge army of creatures, from the mutant fireflys and beetles, to the mighty Dragons, but leading the forces of evil were the Reapers. Fearsome beasts they hungered for the smell of blood, the screams of battle and the glee of victory. They were the strongest and most powerful of creatures, wielding deadly scythes with such lethal accuracy they could best the finest swordsmen. The Reapers stalked the depths of hell becoming restless, waiting to be summoned to battle.
At last the time for evil to rise came. The Dark Gods began placing dungeon hearts in the Hero land. These structures allowed Keepers, evil Humans from another dimension to control the minions of hell. Creatures began to move from hell to the dungeons through portals. But the Reapers remained behind, not wanting to serve any Keeper, but only a Keeper who could prove he wanted a Reaper’s service and could provide for the Reaper’s needs.
Slowly the Keepers began to lose in their battles. The coloured flags of evil fell until only one remained. The Red Keeper. This was the only Keeper who had progressed from land to land without a serious defeat. But he became stuck. The Keeper was trapped in a no win situation. Their were no portals providing him with creatures, but he did have a few that had travelled with him from the previous lands. He also had within his possession a temple to the Dark Gods. The temple contained a font in which a creature could be sacrificed. This sparked the death hungry Reapers' interests.
Hoping the Dark God’s would reward him the Keeper threw his creatures into the font and in doing so proved he was worthy. A reaper appeared at the temple and ultimately won him the realm through the strength of his Scythe and his great lust for battle.
Soon other Keepers arrived, replacing the old. They summoned their own Reapers and vast armies of the Dark Gods' warriors charged at the heroes, and each other. The Rival Keepers in their greed did not unite but split, they fought great battles in which many Reapers died. In the end the Red Keeper won, but by that time only a handful of Reapers remained. The Red Keeper used these to defeat the Avatar, the almighty warrior, and converted the land to Evil. The Gods rejoiced at his triumph but were dismayed by the loss of their Reapers.
The Gods recalled all of the remaining Reapers and instructed them to patrol Hell, guarding it from the forces of good. The Gods now needed more powerful creatures to serve in the front line. They created the Dark Angels in a mockery of angels used by other Gods. The Reapers objected, fearing they may never see a battle again. So desperate were they for a challenge they fought amongst themselves until only one remained; the strongest, most evil, most twisted most psychopathic Reaper who went by the name of Horny on account of the abnormally large horns protruding from his face.
Horny was angry at the Dark Gods; he desired action, but only to serve the most powerful Keeper. Whilst the Gods were engaged elsewhere he created his talisman. He split it into four and scattered it to the four corners of the Realm. When a Keeper dedicated and strong enough to find all for sections was in dire need he could summon Horny to do his evil work. But until that day arises, Horny will stalk the passages of Hell waiting for the Evil one to rise.”
The Warlock placed the book back on the shelf, he would inform his master of this “Horny,” he was sure the Red Keeper could put him to some use.
As I say, this story is not endorsed by Bullfrog, but they do not have their own version so this will have to be taken as accurate.