This amazing postcard came to me via Postcrossing, from Lenka in Russia. The card came complete with birthday greetings (mail between the U.S. and Russia can sometimes take a while), washi tape, doodles and a stamp promoting Russia as the host country of the 2018 FIFA World Cup.
But it's the illustration on the front that is the show-stopper. It's titled "King of the Black Sea" and was done by artist Svetlana Boyko. One of the words on the bottom of the front of the postcard is мифы, which means myths or mythology.
I can't find too much information about Boyko. She used to have a website — SvetlanaBoyko.com — but that domain is no longer in use. I did find some other postcards in the same style at postcardpress.ru, so I believe they are other examples of her fabulous work. They have titles such as Bird Gamayun, Creating the World, Gorynya (Dragon), Lelia Heavenly Goddess, Fiery Serpent Volh, and "Month kidnaps Dawn." All of these are, apparently, drawn from Slavic mythology and folklore.