Boulder Bots are used by the rock raiders to fend off rock monsters. They mainly throw boulders at them to scare them away but if a monster gets brave, they are capable of taking them on with their bare hands. These robots are fairly reliable but every so often They return to base with severe battle damage and sometimes even missing limbs.
Thank god you didn't use the ugly theme colors... This looks much better! Maybe you could use some kind of minifig body wear for the head, to make it more detailed. Other than that this is just perfect. ~M