Haven't heard of Zhu Zhu Pets yet? You will. The furry toy hamsters cost just $10 and slide around the floor squeaking and squealing adorably with the push of a button. Chunk, Pipsqueak, Squiggles and Numnums function in three modes: talk, explore and sleep. Zhu Zhus — the name, loosely translated, means "little pig" in Mandarin — are this year's must-have toy: stores across the U.S. are having trouble keeping the play rodents on shelves, while hard-to-find models are being auctioned for thousands of dollars on eBay. Oh, and they were allegedly poisonous: in early December, a consumer-watchdog website reported finding toxic levels of heavy metals in Squiggles. Federal safety inspectors have since given the hamsters a clean bill of health, which is nothing but good news for Cepia, the toymakers behind the motorized rodent. The small company based in St. Louis, Mo., expects to sell as many as 10 million Zhu Zhu Pets by the end of the year.