Your concept is great...I think I'd take it a step further and have it like a car battery down in his ribcage...make sure you KNOW its a battery, you know?
Yeah, it looks like electronics in action, but the car battery idea might make it more obvious. Something a little more bionic. Otherwise, cool concept. At first I didn't get Christmas because of the color scheme, though. Maybe on white or green. Good luck and an early Merry Christmas to ya. :)
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