"Blood! Why didn't I consider such a possibility! Able to slip into cracks... engulfing its prey to increase its bulk! Such power to be had preying on those around. My creation will demand dominance for me, or will consume them all!"
Fictor labored years, collecting bodies, draining them of their blood. He acquired many vast vats, filling them with the mingled blood of man, creature and beast. Elf, human, dwarf, he cared not. For all lifeblood could be stripped of its differences, until the very essence of liquid life could be instilled in the creature.
Time allowed Fictor to construct the spell that would contain the blood as a single entity. First, he imagined a magical shell that would be as a cup for the blood, but discarded the idea. For dispelling the shell would ruin his creature. With more toil, his discoveries allowed the debased mage to intertwine the blood as one being, one creature. The blood of the creature acted as the surface tension of water- but with a much greater force to remain as one entity.
Victor finally allowed the blood to flow into the pit he'd prepared to use to contain the magicks he would release. He began by melding all blood so that it would fight to remain as one entity, placed strong protective enchantments over the creature, and then instilled it with life, calling on the innate lifeforce blood carried.
He waited for his creation to arise. His work finally at end, Fictor could wait no longer. Drawing a powerful command magic to hand, he touched the creature, to force it to his will.
His arm was drawn into the creature. He tumbled into the beast, into the pit. Having drained the mage's body, the beast moved from the pit.
More blood. It needed more blood.
Blood Beasts are simply described as masses of blood. Although solid, they maintain the liquid qualities of blood, being able to slip into small spaces, expand, and contract. Blood Beasts are horrible sights to see, often causing one to gag and retch. They manifest limbs often, ghostly reminders of Fictor’s original command spell, being able to stand upright, climb, and move as a solid being would.
Blood Beasts are not natural parts of the environment, being created, but they do act serve to prey on natural predators at the top of most food chains.
Blood Beasts reproduce asexually. Whenever a good-sized amount of a blood beast is severed from the whole for longer than a day, a new blood beast will form from the severed part.
A Blood Beast’s single desire is to feed on blood to directly increase its own mass. The blood of any creature with blood will do- cold, hot, alien, human, animal, elf or otherwise, as long as it is blood. Indeed, whenever a Blood Beast kills a victim, it will add to its size a volume of blood equal to the victim’s. Blood beasts move in a semi-solid state, solidifying the portions of their anatomy that will attack enemies.
Carrion animals often follow Blood Beasts. Many an insect and bird has tried to feed off a blood beast, only to be absorbed into the beast.
Blood Beasts carry many blood-borne illnesses within their mass. They are sometimes sought by clerics or wizards looking to study disease. Extracting blood from a beast is dangerous and not often attempted.
The Beasts have weak senses, having almost not capability for sight or hearing. They have a strong sense for blood, much like a sense of smell.
Small or tiny blood beasts may prove unable of feeding on creatures larger than themselves, preying on cats and other vermin first.
Blood Beasts attack anything living. They do not understand the emotions related to fear- their only drive is to increase their own mass. Blood beasts ignore one another- no witnesses have ever seen what happens when two of them touch. Blood Beasts do not vocalize or make any sound other than the sound of churning blood as they move. It is easy to follow a blood beast, as superficial (at least to the monster) trails of blood are left behind the creature, an approximate estimate of the beast’s width can be gained through looking at such a trail.
In combat, Blood Beasts attack without pause, using their bulk to smother and batter enemies with walls of blood. Blood beasts can form arms that are used to bash and smash enemies. Blood Beasts only attack using these physical natural attacks.
In most cases, Blood Beasts try to engulf their enemies within their bulk. Due to the forces holding the beast together, foes inside such a beast are quickly crushed to death. This pressure causes the hapless victim to bleed profusely, immediately adding to the Beast’s strength.
Blood Beasts are weakened in liquids, as they tend to dilute the blood that composes the creature. Blood Beasts instinctively avoid water unless blood is present. Blood Beasts are slowed by cold, even to the point where they can be frozen.
Destroying a Blood Beast is a tricky affair. Most accounts of successful slayings have been done through the freezing and subsequent shattering of such a beast.
Blood Beasts trails persist for days, drawing predators to the area. Such a trail could be a good encounter.
Blood Beasts are often mistaken for Flesh Golems. A party could be asked to remove a flesh golem guarding a tower- when it’s not a golem at all.
Blood Beasts would certainly be capable of consuming horses, a good way of slowing a party down.
Blood Beasts could be kept in pits to use as body disposal units.
A zombie horde might be beset on by a blood beast, making the beast grow dramatically in size.
The beast may be of a size where it cannot envelope a creature that is man sized. Such a beast may be a valued pet- until it grows large enough to threaten master.