This is an illustration by Tove Jansson - who created the Moomins, i like the creatures which are shown
in the bottom - we can see mermaids (selkie, naids, asrai all are very similar!) as well as wonderful yet strange fish. It is interesting how Jasson creates each creature holding a light, as if to help guide themselves through the dark ocean.
The features which have drawn me to this illustration of mythical creatures are the same as those which drew me to the work of Ivan Bilibin - the strong emphasis on detail and decorative qualities.