Two pairs of twin panda cubs made their public debuts at an outdoor naming ceremony in southwest China's Chongqing Municipality on Monday. /VCG Photo

The four baby pandas were named Shuangshuang, Chongchong, Xixi and Qingqing, which symbolize "double joy and happiness". /VCG Photo

The four panda cubs were all born on the same day in June, a rare case in the breeding history of captive pandas, Xinhua reports. /VCG Photo

On Monday, the cute panda cubs also celebrated their 100-day birthday. /VCG Photo