This achievement is for collecting all four pieces of Zurg's body. The four pieces are: Head, Body, Cape and Gun in The Sunnyside Day Care level.
HEAD: Immediately after starting the level, head down the ramp and turn around 180 degrees, and look for a small brown stool. The head is floating on top of it. Jump up and snatch it.
BODY: Turn around and head to the right, you should see a tropical green chair next to some bookshelves/bookcases. You should also see Squishy the Octopus hanging out on one of these bookcases. The Body of Zurg is located on the bottom shelf located in the corner to the left of Squishy.
GUN: Turn around once more, and look for a finger painting station. Looks like a child's size easel. Underneath/inside this easel, is Zurg's gun. You may have to jump to reach it depending on the character you are using.
CAPE: The last and final piece of Zurg is located in the back area of the classroom. You need to use Woody and Buzz together. Using Buzz, pick up and throw Woody onto the counter. You should see Rex the dinosaur. Using Woody, climb up and shimmy around the walls, then jump down onto a green desk. Under this desk is the cape, the final of four pieces.
Easy 25 points.