The Frankenturret, as they're officially called, are the Portal 2 turrets merged with a weighted storage cube. Wheatley had fun creating them in the game, and I'm sure artist corroder666 had fun making the Frakenturret in real life. Best of all, corroder's creation actually lights up. The legs will even move too!
You can see how the Frankenturret came together here, and more of corroder's work can be seen on his deviantArt page. Pretty sweet Screaming Mantis cosplay!
Homemade Frankenturret [Ian Brooks]
via destructoid http://www.destructoid.com/behold-portal-2-s-freakish-frankenturret-brought-to-life-252753.phtml