Nightmare

Encyclopedia Entry:
A type of beastman monster that has the upper body of a woman, and the lower body of a horse. It possesses high magical power, using spells to go into people’s dreams while they’re sleeping. It doesn’t inhabit any specific type of place, and it is extremely rare to encounter one outside of a dream.

While it is a type of centaur, in the same way as the succubi, it is fueled by men’s spirit energy. When they find a man they like, they enter his dreams, appearing in the form of a voluptuous strong willed woman. They take in spirit energy through intercourse. Once they have started to appear in a man’s dreams, they will probably appear again every night and continue to attack him.

However, so long as one realizes he’s being attacked, it would be easy to capture her. Because they approach sleeping men, all one would have to do is pretend like he’s sleeping. They would approach to try and enter the dream without realizing that the man isn’t asleep, and then they could be captured on the spot. In reality, they are different from the strong-willed figures that appear in dreams. They are cowardly, timid monsters, so if they even touch a man outside of a dream, they will instantly freeze up. Given this disposition, it would be possible to tame one after having captured it.