Sphinx

Encyclopedia Entry:

A type of werecat that inhabits the desert region.  Om top of having superior physical abilities like other cat types, it also possesses great intelligence and magical power.  They are charged with the task of protecting the ruins where the “Pharaoh” sleeps, so they attack any travelers who approach.

When they find a man who strikes their fancy, they put a powerful charm curse on him.  The curse is put into place depending on the result of their “questioning.”  If a man answers incorrectly, or finds himself unable to answer, he gets afflicted with the curse.  Men charmed by the curse will probably offer up their own bodies themselves and continue to mate with them as long as they desire.  On the contrary, if a man were to answer correctly, the curse would be reflected back at the sphinx herself.  But in this case too, the sphinx herself will be charmed by the man and go into a rut, which would probably result in her attacking the man and forcing intercourse in the same way as other monsters.

Furthermore, besides using it to apply the curse as written above, they also use “questioning” for other things in their daily lives.  They often make decisions or judgments depending on the outcome.  There’s no compelling force as with the above-written curse, but when negotiating or having a conversation with them, it would probably be to one’s advantage if he were to answer correctly.