Answer:
In a number of cultures, there are myths about magical creatures mating with humans. Sometimes, the gods appeared as half-human/half animal and mated with a desirable human female (in some of these stories, the mating took the form of a sexual assault or a rape of the human female). But at other times, a mythical beast like a dragon would not take a half-human form, and would still be able to have sexual intercourse with a human female. While these myths did not spell out in detail how mating occurred, we may assume that male dragons had sexual organs and were able to consummate the relationship. But keep in mind that there are no dragons in real life, and no such events actually took place. These ancient myths reflected the imagination (and sometimes the fears) of a particular culture.