This fantastic piece was created by Imagine Designs for the 2013 MOCathlon, a yearly online Lego tournament organized by MOCpages. The Reaper statue is fully poseable, with movable faceplates that reveal its laser. You know, for added realism. And terror.
Mass Effect Reaper: I am the Vanguard of your Destruction! [MOCpages]
For reference, here's the Reaper the sculpture was based on.