A G.I. Joe scale custom figure of my Halo fan character, Spartan Marcus Caudill 076. I made this figure using an Iron Man figure and sculpted the other details with epoxy. The weapons were just some random fodder parts I had laying around. Painted using Citadel Paints.
Although, the idea of a 4" scale Spartan is a little silly. The standard 4" figure is supposed to be a normal 6' tall person, and a Spartan in armour is around 7' 2". The regular Halo Spartan figures are near perfect scaled already being about an inch taller.