My COBRA zombies are based on the infected from Left4Dead, and were a fun way to use up some fodder. Most of these parts were ones I had laying around, I tried to only use existing fodder for my zombies without having to obtain new parts. They're quick and dirty but I'm pretty happy with how they came out, especially as a set.
Not a perfect Tank, as he really does still look a lot like just a Grey Hulk, but it works for the parts I had, and I felt the texture of the Maestro Hulk was especially fitting. I was worried the 6" scale upper torso would look out of place, but it seems to be pretty close to the proportions of the L4D tank.
Marvel Legends Maestro Hulk - Torso and Arms
Marvel Universe Grey Hulk - Head, Neck, Lower Torso, and Legs