Head - Duke v3 (1992)
Torso - Duke v4 (1993)
Waist - Backstop (1987)
Arms, legs - Crankcase (1985)
Boonie hat - Marauder Inc.
M16 rifle - Leatherneck v1 (1986)
M4 carbine - unknown

This custom is based on Jarhead's (unfortunately rather badly-drawn) first appearance in IDW Special Missions #10 (December 2013), where he went on a mission with Scarlett and two other Marines - Gung-Ho and Leatherneck. Since Gung-Ho has Force Recon covered, I figured that Jarhead was a Marine Raider, a unit that was revived in 2006 when the USMC created its own Special Operations command structure (MARSOC) as part of SOCOM. You might notice his hair isn't perfectly yellow, but that's intentional to match his comic appearance. I gave him both a classic M16A4 rifle with M203 grenade launcher, and a more modern (and comic-accurate) M4 carbine.