So what do you do when you discover your battlefield trucks are sinking in mud and getting stuck? Simple, you add tank tracks to the back. This MOC by BeLgIuM ww2 bUiLdeR is an Opal truck with Maultier (mule) conversion. When I was a kid, we loved playing with little green army men. I can remember many protracted arguments over who got the half-track. There was just something so cool about a truck combined with a tank.