Sketch based on Caribbean octopus.
Medium used: Ballpoint pen and coloured pencils
Reference: https://www.petesaquariums.com/shop/invertebrate-fish/octopus/caribbean-octopus/
Second up in the "uploading progress pieces since I get questions about my art process" is a Teenage Mutant Ninja Turtle print I'm working on for a convention. This is the rough sketch, next up I'll clean it up and do my guide lines for inking. Hopefully I won't have to redraw Donatello