Select a good image with contrasting colors important and create a new layer and start making polygons with the pen tool
The idea is that you create a grid of polygons and which resembles the figure of the animal
After completing the grid is good to check if the polygons are all aligned with each other, then this process can begin painting
Coloring just have to select the dropper tool and look the right color of each polygon
For this last part is the process photoshop which adjust the colors and look good color for the background, we can also add some nice detail, etc.
Our work is completed ;)
