Some sort of patrol 'bot. Design based on this, mostly.

More on Flickr or Brickshelf

What a very cool and original creation, elegant, detailed and inspiring. S.F. pure!

I agree with Asuka, but would only add that there is something about it that I find creepy. Before I checked your reference photo, I thought it was a mechanical version of one of those Dark Crystal landstrider things

...which are also creepy.

Nice, but some arms would make it look even better.

It reminds me of the strider from the half-life games.