Ling Ling and Chang Chang are a pair of zoo humans in the Dinosaurs episode "The Mating Dance." Attempts to mate the pair have failed continually. It is feared that Ling Ling is barren, and Chang Chang is sent to Mel Luster's Mating Dance Academy as a last resort. Referencing real-world problems with panda mating, the joke lies in the fact that Ling Ling and Chang Chang are both bearded males. They are named after Ling-Ling and Hsing-Hsing, two pandas who were given to the United States of America as gifts from China in 1972.