I've created a monster.
Now you can too!
This Lyco can create scary monster, cute monsters, monster girls, and so on. YMMV if you ask it for standard monster types (it's not really trained on specific named monsters), but it's very creative and will come up with some cool and original stuff.
Usage tips:
I honestly like this model better for creating cuter, more colorful monsters. It's very good at them, as long as you mix in something cute. I like it a lot with Envy Cute Mix 11, but there are a lot of other ones I haven't tried, so go crazy with it. Generally I don't mix in other loras and lycos in my example images, but I'm doing it here because they're an important part of what this model can do.
Add '1girl', 'cute', and 'female' to your prompts to get monster girls fairly reliably. Again, though, this is better at creating novel monster girls than the types you'd recognize.
'1boy' and 'male' work too, but a bit less consistently.