

If the hybrid is a negative character, this will make their inhumanity more personal. Females tend to be luckier in this regard than males, due to being seen as an exotic beauty. Frequently it's because of self-image issues, possibly due to people getting freaked out at them having horns and hooves or the like.
HALF WING HALF HEART PLUS
Being a Half-Human Hybrid is almost always a plus for protagonists, although the characters usually don't think so. A half-vampire might pick up Super Strength and Voluntary Shapeshifting without having a weakness to sunlight or a thirst for blood, for example, or a half-elf gets magic and an extended lifespan (funny, that). Positive characters also tend to pick up all the advantages and powers of their component races with no disadvantages or weaknesses. or at the very least, they'll have the power to fight one-half of their heritage, almost certainly if that one-half is vampire. If the hybrid is a positive character, it connects the audience with them, giving them familiar characteristics and a closer point-of-view into the otherwise alien culture, or else, an "outsider" character for protagonists to befriend. Sometimes a particular type of hybrid becomes common enough that they can stop relying on their parent races to make new members and just mate with each other to sustain their own race. After all, What Measure Is a Non-Human? and the hybrid's very existence is proof of a lack of Species Loyalty. Rarely does either species accept the mixed marriage, much less said hybrid, though. A Wizard Did It is just as handy a Hand Wave. Good thing there are No Biochemical Barriers! And if you can't find a scientist to do it for you, you're in luck. Thankfully, the Rule of Cool and Rule of Sexy let us mix it up with whatever the Green-Skinned Space Babe's ancestors evolved to store their genomes in. It requires a lot of supporting stuff in the cells, and not even everything on Earth uses it. That's Earth's solution for storing your genome. They'll do it even if there's no reason to think the creature should have DNA in the first place.

If they are not physically viable, rest assured there are scientists somewhere who will fiddle with DNA until a hybrid is created. The mother is in a majority of cases the human, with the non-human father providing the powers. Demons, elves, aliens, vampires, you name it not only will a human sleep with it, they'll engender children. In fictionland, human beings can conceive children with any intelligent species in existence. This makes it extremely unlikely that creatures of different planets would be able to interbreed, but then again, Mars does need women. In reality, many closely related Earth species share over 99% of their DNA, but cannot produce viable offspring. This is present in most unrealistic fictional genres, including Science Fiction (or, rather Space Opera), fantasy, horror, etc. The results of an Interspecies Romance and/or LEGO Genetics.
