"The Big Bang Theory" Soft Kitty Plush brings to life one of the most memorable recurrences from the Emmy Award winning sitcom. Adapted from the song of the same name, the original ditty has propelled Soft Kitty into pop-culture phenom status. "The Big Bang Theory" Soft Kitty Plush is officially licensed and features a built in speaker. Just squeeze the front right paw and Soft Kitty sings Sheldon’s favorite lullaby. Launch date: 2011.