I've been making mermaids for years: a personal fetish, in the best sense. I've given more than a few away to friends: the perils of having a clay-maker as a friend! Bowls are usually welcome gifts, but sculpture . . . . that's trickier, more demanding of the friendship.
My first efforts emphasized metamorphosis, emphasized strenuous, painful transformation. They all tend to be rather ugly, from a narrowly human point of view. I like them, warts and barnacles and all. (I made a dancing mermaid once, who wasn't ugly, though slightly flawed in the glazing. She has a good home.)
Here, I like best the Amazon with shield (redwood bark) and stone (beach pebble). Sculpture mix or stoneware; the basic glazes; copper wire. I make mermen too, just not as often.