Hybrids

Hybrids are the results of successful interbreeding of different species. Hybrids can come in many, many different shapes and forms, depending on the species of their parents, and the mixture of DNA. There is concrete base for what hybrids will look or behave like, or what abilities and attributes that they will possess. That said, there are oftentimes common themes. Some species, however, cannot make hybrids.

Difficult Species
Some species cannot create hyrbids, or only create hybrids under certain circumstances. These species include:
 * Incubi/Succubi: Incubi and succubi cannot make hybrids, as the resulting child will always be an incubus or succubus. This is because "purebred" incubi and succubi cannot exist, as the species cannot reproduce with one another without causing physical harm or death.
 * Werewolves: Werewolves can create hybrids, but only if the parent is male, as females cannot bear children without miscarrying due to the forced monthly transformations. Werewolves also cannot create hybrids with humans, as the resulting child will always develop lycanthropy during puberty.
 * Vampires: Vampires can create hybrids, but only if the parent is male. This is because females due not menstruate, as the bleeding would cause them to bleed to death. This aside, it is rare for vampires to create hybrids successfully, as the foetus will drain the life energy of the mother, causing death in both mother and child. Should the mother not perish, she will most likely suffer permanent health complications and have a significantly shortened life. Successful birth is unlikely, but on rare occasion, a child may survive.
 * Elves: Or specifically, certain subspecies of elves. English elves can create hybrids, but Nordic elves cannot create hybrids with humans. Offspring will always be an elf.

Dangerous Species
Hybrids between certain species will often result in dangerous creatures. As horrible as it is to say, these species should avoid reproducing with one another, or risk exposing themselves and other to danger with the resulting offspring.
 * Demons and Vampires- These are rare, as neither species requires sexual reproduction to exist, demons seldom have the desire for sexual or romantic relations, and both species are oftentimes aware of the risk through stories. Vampires in particular share stories about the nightmarish and savage creatures that come from the union of their species. Demon/Vampire hybrids often have grotesque appearances, but can change shape in order to lure prey. They are not as sophisticated as either of their parent species, however, and have no desire for socializing. Thus, they do not behave like humans and seem "off". They only wish to eat humans in their entirety; their flesh, their bones, and their soul in all. All tales that tell of their existence end in their inevitable death, as their terrible reigns are swiftly ended by other supernatural beings. The instinct-driven nature of both species with both of their power combined is deadly.
 * Demons and Divine Beings- These are also rare, as these entities often clash with one another, but so do their genes. Children resulting from either a demon and an angel, or a demon and a grim reaper often suffer from violent impulses and the urge for combat. Oftentimes, they will focus on one person and be bent on their destruction. In some cases, this can be one of both of their parents, or even another child. When successful, they suffer from severe depression until they find their next foe. They are not erratic, however, since they are often as calculating as they are sadistic. These hybrids will set a stage for themselves and their target before they plot to take them down, taking delight in the whole endeavor.

Health Complications
Some species suffer from serious health complications, and sometimes, giving birth to hybrids can be dangerous if the mother's anatomy cannot handle whatever it is that is made. Hybrids can be subject to various physical and mental impairments, and are actually quite common to get both parent's weaknesses.