This is a story taking place in a fantasy world with many beings and creatures that don't exist in real life, like mermaids, demihumans, elves, dwarves, and even mythical beings.
Many things can happen.
 
Don't know what a demihuman is? Basically a catgirl or catboy, but sometimes animals other than cats, they biologically make sense. The wild ones don't wear clothes, since they have no need for them.
Thats the only custom creature here, the rest are from folklore you can search on the internet.