This papercraft is
SD Walker Galliar, based on the
Combat Mecha Xabungle anime series, here's an SD version of the giant bazooka-toting walker machine known as
"Walker Galliar". The designer Shirokuma for this great model and for the heads up. The pattern isn't up yet (as of this post), just bookmark the link and check back in a few hours.
You can download at here:
SD Walker Galliar Papercraft