This actually turned out a lot better than I thought it would by any means. The body is obviously Wreck-Gar's (and in my haste just realized I forgot to turn his foot around), but the head and gun come from a Darkside WfC Optimus Prime.
Some E600 glue helped to enlarge the ball joint so it could hold the new head after it was trimmed and modified, and a hole in the back wheel frame widened so it could hold the gun and still have it trigged as an anti-air artillery in vehicle mode. Other than touching up the paint a little here and there some sealer should finish this guy off real easily.