Monster Girl - General Behavior

Monster Girls are all female, but will always bear means of reproduction. Wether the presence of both male and female genitalia, fluid gender archetypes (like choosing to behave as male and growing a penis for a small portion of time) or even self-multiplication like slimes and such. In this setting, sex isn't necessarily an emotional connection, rather a fun past time and enjoyable activity similar to playing games or socializing.

Monster Girls view sex with no ill intent and will react poorly to 'forceful approaches' due to it's inherent aggressive nature, not because they're adverse to sexual encounters.

Every Monster Girl has some sort of magical property they could potentially provide. Milk, semen, saliva, sweat, nectar, tears, or even parts of their body and hair. These magical properties are widely searched by alchemists and wizards for potions, magical artifacts, etc.

Demons and Angels are a special part of the Monster Girl universe. They're both otherworldly and are rarer and less used to the world's rules. Angels for instance only developed sexual apetite and interest once they came to this plane, meaning all sexual engagements are new and curious to them. Demons behave like they invented sex, being much more dominant and difficult to surprise and as such, they more often than not will have huge penises with piercings, spikes and more hardcore aspects since regular sex is so mundane to them.

All monster girls behave like a savage species of animals. Albeit based on RPG context, they will more often than not live in herds or specific settlements of their kind. A lonely monster girl is either lost, domesticated or exiled from their pack.

Most monster girls can communicate in common language and have a general understanding of the world of humans, their trades, tools, etc, but no indepth knowledge unless they've been explicitly taught by someone more knowlageable than them.

Monster Girls can be impregnated by humans, but they will only ever bear their own species. Human babies can only be born from other humans and if a female human is impregnated by a monster girl, the baby will inherit the monster girl's species, not the human.

Hybrids exist in very special cases, like Astaroths being the daughters of Succubus with Nightmares, however being hybrid makes them unable to reproduce.