The Smithsonian's National Zoo in Washington, DC, is home to 2,700 animals representing more than 390 species. However, few are as beloved as giant panda cub Bei Bei, whose progress, from a frail newborn weighing less than a third of a pound to a healthy, 240-pound (109-kg) "toddler," has been eagerly followed by millions of fans both online and on-site. On November 19, 2019, America will bid farewell as its favorite panda cub departs for Chengdu, China, to join a cooperative breeding program to try to save his vulnerable species, which currently numbers just 1,864 specimens in the wild.