From Ikea’s bedding line, this duvet cover and pillow slips are called “Eivor Leava”. The sizes are twin, king, full/queen and the set is $49.99. According to Ikea’s site, the inspiration for this comforter came from “Sweden’s rich tradition of using textiles as a means of storytelling.” By the way, “Leva” means “to live” in Swedish.
Thanks to Aleks H. for the photo and the find!