Rowena Morrill gives us virtually everything we want - demons, winged creatures of the night, alligator people (with boobs!), creepy landscape, and yes, a naked lady - for Jane Parkhurst's 1977 occult/witchcraft novel Isobel (which I haven't read), and can you believe it was Morrill's first cover? How would one ever top this?!
Warriors of Terra by John Faucette
32 minutes ago