This image is fanart, we really wanted to make that item for environment in 3D like cartoon by hand painting.
First We sculpt and polypaint it with Zbrush I really like to start in ZBrush because you get results pretty fast. It is very easy and practical to make design changes with ZBrush. After I had finished the blocking-in I exported the OBJ file into Maya and started the retopology process for Low poly and UV. Genaral maps: diffuse, normal include Normal with xNormal and Zbrush.
Photoshop I mix the base color I made in ZBrush and xNormal. Finish hand painting in Photoshop.
Render in Sketchpad.