2006 G.I.Joe 3.75 " Convention Set "Cobra's Most Wanted: Mercenaries!" Boxart

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From MasterCollector:

The Mystery Figure will be revealed SOON! In the meantime, here is a preview look at the 2006 Con Set box art! The final figure remains shrouded in mystery on this preview image. This IS NOT the final art. The next update will show the full box top image with the center figure restored. Shortly after that you will see the actual figure itself! Who is the mystery man? Judging by his target and the SINGLE shell casing, he is a dead shot!

Update: The mystery character on the box is revealed. It appears to be Cobra Mortal, which was orginally an extremely rare Argetine figure. Confirmation on this character will be released soon.