Polish artist Beksinski
(1929-2005) created abstract and surreal art in a variety of media, but he’s best known for the fantastic, sometimes disturbing paintings he produced in the 1970s and 1980s. 
Skeletons, corpses, sinister shadowy figures, dark landscapes, and looming cliffs and buildings abound.
Speaking of these paintings in particular, Beksiński said, “I wish to paint in such a manner as if I were photographing dreams.” In some cases, he seems to have succeeded.
Beksiński moved on to digital art in the 1990s, and was murdered in 2005. There are a few online galleries of his work here and here.
