Conan the Barbarian.
The image on my cover is digital art. Like most of my work, it's a combination of 3D models created in ZBrush and Blender and then retouched in Photoshop.
Now, my cover definitely isn't a real painting. It's a combination of 3D models and a lot of retouching afterward in Photoshop trying to imitate the style of a painting. There are several examples of this hybrid work method between 3D and 2D on my Artstation