First I'd like to thank Randy of Cannibalized Action Figures for coming up with the Flood-swap-technique that he used on his Jackal Flood Form.

I did about the same thing here, removing the top portion of a McFarlane human Flood form, attached it to the Elite lower half, modded on all the armor, sculpted some extra Flood sections for added bulk, modded the Elite head hanging over on the side, and added Shelob's spider legs for the longer claw on the left hand. I also replaced the sensor tendrils on the front with bendy wire so they can be posed. Looks pretty much just like the ingame model I think.