After 501st legion stormed and destroyed kamino's cloning facilities some clones escaped. On the run and out of parts they had to salvage what they had. This lead to the creation of the battle striker, made from the parts of two clone walkers and some small 2x2 bricks.
About this creation
I think this is the best photo of the battle striker. You can see the large turret thing at the back (It has three heavy laser cannons and three missile launchers with 4 mini rockets each). You can also see that the walker is driven by a clone pilot and a clone gunner. The two heavy repeating laser cannons at the front are powerful enough toblow up tanks and its powerful legs propell it fifty meters into the air and its feet allow it to cling to any surface, no matter how slippery or smooth it is.
Another cool picture of the weapons. Sorry that all the photos are crap and blurry but we have a carp and broken camera (oh well). You can kinda see how the legs are attached from here. They are mounted on a 2x6 plate and frequently fall off but that makes it easy to make pictures of "destroyed" battle walkers (see below) and put back together.
This shot allows a clearer view of the way the legs are put on. The symbols are from the original and the ones at the back are the parts from the mini millenium falcon.
This rear photo shows the major blind-spot for the battle striker. The big turret thing blocks a rear view. Even though the battle striker has a rear view camera and scanners it is still vulnerable to rear attacks.
Not much to say here but you can see the 2x6 crossbeams that the legs sit on.
"Watch out, there's a tie defender coming to blast you" cries a watching clone trooper.
But the warning came to late. Even the great reflexes and incredible speed of the battle striker isn't enough to dodge the lasers and it is blow to bits. "Oh well it just didn't move fast enough" sighed the clonetrooper
This pictures wa just for fun. It shows the battle striker standing on top of some trampled enemies (I used some storm troopers and some exoforce droids). The clones better savour tne victory because it'll be there last before the empire bombards the planet with anti-matter bombs.