i dont see a 'monster_girl'. unless your telling me that those red snakes are coming out of her arse & pussy and into the other girl, which i doubt. Just looks like 3 snakes raping 2 girls
Check the other images in character tag Melusine. The actual legend can have a half-serpent body. In FFV art she is depicted with a fully human body, and the snakes are basically external symbionts she controls. (A little bit like Echidna in Queen's Blade.)
The eyebrow raiser is that there's two black snakes and only one red snake. She is a fiend after all. ;)
