Gray Fox, formerly known as Null, was the codename of FOXHOUND agent Frank Jaeger. Originally a child soldier for FRELIMO, he was the only active field agent of FOXHOUND to achieve the codename "Fox," FOXHOUND's highest commemoration, and was decorated five times. Fox was Solid Snake's war buddy and best friend after the Outer Heaven Uprising, but Fox's loyalty to Big Boss forced him to betray Snake during the Zanzibar Land Disturbance. He survived his injuries during his battle with Snake and was outfitted with a powered exoskeleton and given intense gene therapy. He confronted Snake as a neutral force during the Shadow Moses Incident before dying at the hands of Liquid Snake via Metal Gear REX.