If you haven't realized it already, MASSIVE SPOILER ALERT.
This is a plush toy of Potato GLaDOS I put together for my girlfriend for our anniversary (because Portal 2 is the game for couples). While she was plummeting through the bowels of Aperture in single player, she mentioned how sad she was she couldn't just pick up Potato GLaDOS and sympathetically hold her, so I decided to make her this stuffed animal that she can hug all she wants.
I only had a few days to put this together, and I was away from home without a camera, so I didn't have the photos for a full instructable at first. I have since made a second potatOS and posted the complete step-by-step here.
The potato is made from camel (brown) fleece. The red LED's and alligator clip insulation as well as the yellow "eye" are made from colored fleece bits left over from my Lady Rainicorn project a while back. The white computer parts are made with a mystery fabric I found in the scraps bin, stuffed with pieces cut out of blue camping pad. The nails and alligator clips are scraps of felt my mom just happened to be getting rid of. The black wires are cotton jewelry string, and the yellow wires are string that I happened to have. No idea where it came from. I used black embroidery floss for the circle pattern on the front as well as the wire sticking into the potato from the computer chips.