Bo Peep is a Premium Box Tsum. She is currently only available on the Japanese version. She is a Limited Event Tsum and is not available from purchasing Premium Boxes outside of the event. She was first introduced during the Japan Event Tsum Tsum Toy World (July 2019).
Bo Peep will clear surrounding Tsums when you connect her in a chain! Her number required is 20 and her base size is SS. Higher Skill levels reduce the number required.