Angels who work for Death, but can also answer to death deities of the Judeo-Christian/Roman/Greco pantheons. It is unknown if God created them with the rest of the angels, and gave them to Death, or Death created them in the image of God's angels. Regardless, they assist in maintaining the Natural Order & used to be thought of as completely neutral, aligned with neither Heaven nor Hell, nor Purgatory. Their presence is required for a death to occur, waiting until a person meets the end of his/her life (either through accident, intentional, or simply natural causes) and then by touch, release the soul from the body. They then escort their souls to Heaven or Hell. They do not however, possess the power to force souls to go, therefore they must convince them to depart. Although sometimes uncaring, Reapers generally sympathize with their victims, but refuse to make allowances, regardless of who or why. Often times Reapers are friends with ghosts who have refused them in the past. Rogue Reapers do exist, who ferry souls out of their afterlives & take them to a different one, for the purpose of profit. Reapers are able to possess humans, usually to manifest physically for humans to see them, in their true form they are invisible to all but ghosts & other supernatural creatures. When they possess a human they are vulnerable to angel blades, and can no longer only be killed by Death's scythe.
In Ancient Africa the first slayer was born when a young girl was given the heart & soul of a purified demon, granting her enhanced strength & senses needed to battle evil. The Slayer legacy is not genetic, as they are chosen by a divine power & bestowed with the responsibility of protecting the innocent. They are figures throughout history & have retained a degree of notoriety in demonic circles, assuming a "Boogeyman" reputation. Slayers have to be trained by a Watcher & tested before the Council before officially taking the role. The relationship between a Slayer & a Watcher can take on many roles, but one rarely survives without the other. Up until 2015, Slayers were never chosen more than two at a time, but as the supernatural threats have increased in number, so have the Slayers. They are known for working with & are more accepting of other supernatural beings than Hunters.
When an angel does the dirty with a human, you get a Nephilim. They are forbidden & seen as abominations by many factions. Nephilim have glowing eyes like an angel, although their glow is somewhat dim & grayish in color as opposed to the bright white or bluish-white glow of regular angels. They can look upon the true form of Angels without harm & possess superhuman strength/durability. Unlike regular Angels, they do not have Grace & thus do not have wings either. If a Nephilim were to steal an Angel's Grace, they would receive wings & have access to Angel Radio. If an angel who has fallen or lost their grace mates with a human, the resulting offspring will be completely human.
A dark, ghastly, malnourished looking version of Merfolk, Siren's can take on the form of a human but their true face can always be seen in a mirror. It can lure victims by singing and then manipulate feelings of love, whether sexual or platonic, and even cause its victims to kill someone they love. A siren's kiss will doom the human it chooses, it infects them by fluid transfer. The infection leaves traces of oxytocin in the victim's blood - a love hormone that provokes feelings of euphoria. They feed only on humans they can trick into loving them and can be killed by a bronze dagger dipped in the blood of someone under its spell, or someone whose found their true love.
Originating from Scotland, Kelpies are known for being a beautiful steed inhabiting freshwater lakes, ponds, and streams. They lure victims to the waters edge before dragging them in, devouring them, and tossing their entrails onto land. Males tend to dominate the species, and wherever a Kelpie is, fairies are usually close by. In true form, the Kelpie can take its victim to the water on its back, or drag them unwillingly via adhesion to their skin. By cutting off the tail of a Kelpie they can be trapped in human form and drown unless reverted back by a witch, they can also be stuck in their true form by removing the silver necklace (bridle.) A silver bullet will kill it in either form.
Either male or female human/seal hybrids who search for human companions. By shedding their sealskin, a Selkie can live on land for up to 6 months before having to return to the sea. If a Selkie's skin is lost or damaged and they are unable to return to the sea in time they can die without magical intervention. They are very monogamous, tragically so, and would go as far as to throw themselves to the cliffside at the loss of their loved one. They are often friendly toward nymphs and fairy creatures, and some have been known to feed on human flesh.