Hi, it's Cpl Harriger here.
One of my friends in my unit drew this tattoo himself. I originally only had the USMC, but felt that more needed to be added. He has his own tattoo parlor in NY, called Chris Tattoos. He's done mine, and 8 other guys in my unit here at MCB Quantico, VA Track Vehicle Platoon, all original works of art. We nicknamed it Swamp Bitch, for those of you that can't really tell.
He is wearing a boonie cover with branches attached to it, the lines leading from his eyes is supposed to resemble smoke to give a more possessed look to it, and yes, although you can't see all of it, he is biting down onto a trusty k-bar, which gives a somewhat tribal appeal to it as well.
Oh RAH! And Semper Fi!