The small band of rebel troops left behind on Hoth for a short time before evac found a weak spot on the Imperial AT-ST walkers: a perfect hit on the knee joint would break the fragile walker leg. After the snowspeeders ran out of ammunition the pilots flew the speeders dangerously low, directly through the legs of the walkers. The armored speeders could take the hit easily, the walkers couldn't.
This has the most complicated rigging I've done so far, the legs of the walker were detached from the top and the left leg was further divided into smaller bits. The speeder, the walker and the little bits were hanging from a support above the frame. The problem was that I hadn't done these for a while and I kept missing the baking powder plume over and over again. It is really fast. I also made the mistake of attempting this when I really did not have the time to do it patiently. This is the final frame of the session where I just threw everything on the setup in a heat of frustration and, incidentally, the only frame even close to what I had in mind – and it had my hand in frame on the left top corner.
After some unusually ample Photoshopping, I think it came out quite nice.
On a lighter note, there's another snow lantern building trooper here. I just dig those guys, I think I have to take one with them only. :D