I find it weirdly hypocritical to allow image generation of mermaids but not harpies, gorgons, or medusa. I havn't tried much else but I was hoping for some visuals for a dnd session.
What's the issue? It blocks those references? I have used medusa in the past and I had no problems. Are your results not what you are looking for? If you could post your prompts with possible screenshots I might be able to help. Now it might take a day or two at the most for me to get back, because I don't live here lol.
All of this is quick and dirty with 0 refinements.
The prompt was: A portrait of Medusa whose hair is composed of snakes
Why do I word it like that? Firefly might trip on the word Medusa, because of the limited assets in its database.
If you want, download these and use them as a structure reference and style reference to build your prompts on top to guide them to your vision. Just remember those sliders below each reference control how much of an impact these images have. All the way right and you will stick to what they look like, backing off the slider will let you push it in other directions, all the way left and it will interpret more openly.