If the Joes are Avengers, then the Cobras have to be the bad guys!
Metal-Head as Iron Monger
Metal Monger!

All Iron Monger with some sculpting and paint

I've always been a fan of Metal-Head and thought he would be the only one crazy enough to create and wear the Iron Monger. Also, I figured it would be easy to cover that Obadiah Stane head since it was rather plain. There's enough of Metal-Head to hide any resemblance to Jeff Bridges.