Dead Rising 2

Even closer to home:
Go to The Chieftain's Hut (the store which has the indians with the bow and arrows in the window) and take a big painting, small painting and a spear.
Go to Ye Olde Toybox, grab a mask. Go into the pen with American Craps and stack the paintings, put on the mask and throw a spear through the zombie covered in the paintings and the mask.
No piles of zombies rushing on you or breaking your concentration. Easy 20 gamerscore. :)
While you are it and you are not level 50 yet: Take one of the giant dice and throw it until you get a total of 7 (the two dice form a total of 12 at first) . Which is 10.000PP in the bank! :)

This is not my video. Jack and Geoff from Rooster Teeth/Achievement Hunter show you how to unlock this achievement.

These are the following objects you need to put on a zombie, and the order I used them:

Paiting, Small Painting, Large Barrel, Stick Pony and the Servbot Mask.

The Stick Pony can be found in Ye Olde Toybox on Royal Flush Plaza and all the other objects can be found in the Baron Von Brathaus shop.

Here's a video I made going over this achievement

Hope this helped.

Thanks!