Atlas

Some Thunderbolts beefcake scans courtesy of Dermie!

According to him:

Atlas from THUNDERBOLTS #13. The T-Bolts are trapped on Kosmos, and Erik is recapping his experience with the Kosmosians for his teammates, up to the point where he was rescued from Kosmos by Zemo and the others (in the last Atlas scans I sent you). It seems the Kosmosians like Atlas with his clothes off, since in the incident he was in his briefs, and the next time he was naked. Unfortunately he manages to keep his clothes on during this visit.