Head - Mortal Kombat Johnny Cage
Torso, Arms - Skidmark
Waist, Legs - Tunnel Rat v3

Submachine gun - Shockwave v3
Phone - Firefly v4

Spook is an original character, who serves as the CIA liaison to the G.I. Joe team. To me, the Johnny Cage head from the 1995 Mortal Kombat figures just screams "CIA", and the rest of the figure came together pretty quickly. I did this figure a while back, but made a recent improvement when I acquired a Molotow Liquid Chrome pen, which allows Spook to have reflective sunglasses like the CIA are wont to do.