For game requests, you sould post to the "Recommendations & Identification" forum. There are way more people there willing to help you.
As for your question, the only really big game out there about fucking creatures is
Teraurge, no questions asked. If you're really desperate about female creatures/ferals, there's also
Sexy Mythical Beast Adventure. The sex scenes are alright, but the game overall is really bad. I don't recommend it at all. If you accept Pokemons, there's
Monster Addict, it's barebones but it has that kind of content, and also a link to a webcomic about the exact same kind of content.
