I never heard about this variation, it seems weird as this is a figure from 2005 that had two known variants with the all-white and the Shocktrooper (red) deco. So a third one should have been documented as well.
So either the camo one is the rarest figure in the world, and way underpriced, or it is a (honest or not) mistake and it is simply a custom that was well recarded.
It's ULTRA rare, only one exists - it's a custom. Someone painted it and recarded the figure - you can even see some residue from the original piece of tape on the left side. Likewise, this deco pattern was clearly not made by a Hasbro factory.