Various artists
Toucam
Artist's deviantART profile https://www.deviantart.com/toucam/.
Images were painted by fine line marker and colored in Gimp.
Escheresque
Although the image is named as "Escheresque", here, there are strong influences of
Oscar Reutersvärd and Regolino Bizzi
rather than of M.C. Escher.
Penrose cube