I used a MU greatest battles Cyclops. I changed the arms from the shoulders down, as the Cyclops ones looked way too short. I then sanded off his visor, and sculpted the armour and helmet out of the 2-part epoxy. One paint job later and we have an MU Avalanche.
Post Revision - I was not happy with the way this figure showed when I first posted him, so I went back, cleaned up some things on the sculpting, and added some highlights to the paint job. I'm much happier with the outcome now.