But what about my Kabeiroi? He's similar to a aasimar, as he's a dwarf descended from the dwarvish sons of Hehaestus...
In fairness, the
Kabeiroi are explicitly only two, and it's well-known that descendants of gods (or other entities e.g. titans) have a complex relationship with their divine parent(s) in terms of physical similarity--and other myths (such as those of Aeschylus), the
Kabeiroi are explicitly gods themselves, not mortal descendants of a god. The
Spartoi are repeatedly cited as being the result of what happens when you sow a dragon's teeth, and some of them went on to explicitly be the ancestors of existing groups (e.g. I believe one group of
Spartoi--possibly Cadmus' group?--were held to be the ancestors of Thebes.) You also have myths like the
drakaina, "dragonesses", who were apparently part-human, part-serpent, and capable of producing viable offspring with humans; one myth posits that the Scythians are the descendants of Hercules and a
drakaina, for example. Finally, you have characters like Erichthonios, who was frequently depicted in late-Antiquity and Medieval art as having a half-reptilian body. Not a far leap from there to a "half-man, half-dragon" form.
But I take your point: it
is worth noting that oftentimes, things we
think are so utterly alien to a mythology are not quite as alien as we thought. Post-Christianization Welsh mythology, for example--which contributed to the Arthurian cycle--includes the idea that a person can be sired by a demon, specifically an incubus. Some legends about Merlin claim that's where he got his powers from, but because his mother was devout, she had the baby baptized in the very hour of his birth, and thus he got all the rad demon-powers with none of the corruption.
I used the example of Greek myth specifically because I've dug into this one rather a lot over the years, and found not just one or two, but
several myths that speak of dragon-human offspring, or children who were "born" (sometimes from the Earth,
autochthones) with reptilian/draconic characteristics, or a people specifically linked to reptiles/serpents (e.g. the
Ophiogenes, the "serpent-born", which yes, that
literally is the term used for an alleged tribe of people in ancient Greek myth.)