Medusa Mech

I don't know about the practicality of this design by d' Qiu Brick, but who cares, it's awesome. I would think that having those snakes whipping around would throw the center of gravity all over the place, but can you imagine the looks on your enemies faces if you showed up piloting one of these? They'd soil their jumpsuits! 

Serpentine Hall

Within the LEGO community we tend to glorify new part usage but not always unique MOCs that fall outside of the normal LEGO themes of space, castle, city, Star Wars, etc. Builder robuko has succeeded in both NPU and building outside the box with his latest creation, Serpentine Hall. While technically a castle build for the ongoing Eurobricks Guilds of Historica building challenge this structure transcends the classic castle theme and really puts it into a class of its own.