Yes, with the help of a number of modifications, one studious KSP fan has managed to build a bipedal death machine, complete with missiles and ballistic weaponry. As impressive as that is however, the drop-ship that brings it down is perhaps even more so, and there are tanks for it to shoot at once it lands, too.
All of this destructive construction was made possible thanks to a combination of mods that include: BD Armor, Infernal Robotics, Camera Tools, Tweakscale, Steam Gauges, KOS and UbioZor Part Welding. It took over 20 hours for the user behind it all, Allmhuran, to build the rather iconic walker, and then a further two weeks to make it walk correctly, according to PCG.
As wobbly as that walk may be, he did indeed manage to create a machine that was never designed to exist in a world full of liquid fuel rockets, but it does. The only downside is that unless you are willing to take similar steps to construct your own walking monstrosity, you won’t be able to play with this mech, as the creator has kept the files for himself.
Still, there are a few days left until Kerbal Space Program 1.0 officially launches on the 27th. Perhaps you can put something amazing together in the meantime.