These inexpensive robotic hamsters became a recession-era favorite in 2009 when they were named the hottest toy of the holiday season. Officially priced at an affordable $10 or less, Zhu Zhu pets were in such high demand that at one point they were selling for thousands online. Created by Russ Hornsby, nine different Zhu Zhu characters could be activated into a nurturing mode, in which they snuggle and coo just like your average hamster but without the smelly cage. The "Zhu-niverse" now includes a line of Zhu Zhu babies, puppies and even ninja-like space fighters.