For the second day of Christmas, I've pieced together something a little more defensive and less mobile.
Phoenix Company is mostly a ground force in the original UFO: Aftermath canon, but they're also avid users of collapsible machine guns. While I'd love to re-create that here (and might do that in the future), an automated sentry gun seemed more appropriate for repelling whatever creatures crawl out of the Bioamass.
The soldier had to use a normal guardsman torso, but I couldn't cover it up with the arms due to the pose - instead, I've added pouches and other minor pieces to try and bulk up the front, making the flak gear look slightly more combat-amour-like.
The boxes on the base are a minor detail, made from one of the normal ammo boxes and some scrap parts. I didn't want to connect it to the gun itself, since I liked the idea of having them strewn about like they had been scavenged.
A lot of the parts used here were taken from various Tamiya tank kits, mostly smaller details on the front of the weapon and the extended barrel.
The backpack - a standard Spellcrow one - required some extra pieces underneath to fit properly. Since the operator here is unarmed, it made sense to choose one that had a knife and a few grenades, especially since grenades in UFO are completely viable as a trooper's only weapon.