When you enter the Forest Kingdom, you will encounter a strange, skull-like ball inside a machine you destroy. After you're done, you'll find this creature, Emil, roving around the City Ruins in a mobile shop car.
As your Pod will suggest, shoot him to make him stop. Pod C's missiles do the job nicely. Simply view the shop to get the Trophy - no need to buy any of the +3 chips that cost 21 slots to use, since they aren't really worth it (unless you want to buy your way to earning Chip Collector).