So I was messing around with soldiers, and this thing spawned (I naturally gave it items for sake of screenshot). But what is this? Also if you want to dupe it spawn regular yellow soldiers until it spawns.

(Front view)

It's an easter egg, a rare skin.

Every team has one or more rare skins, some have one or more unique ones as well.

Also these will be accessible via another method in the future.

I see, thank you for responding, I did not know there were easter egg skins