She won't make her first public appearance until July, and already, Germans are celebrating with stuffed-toy replicas. What is she? A crossed-eyed opossum named Heidi. The craze started when photographers from a German tabloid took photos of animals to be featured in an upcoming zoo exhibit in Leizpig. Heidi, with her permanent expression of deranged concentration, became an overnight sensation. The zoo created a new page on its website answering questions about her. A German songwriter who saw Heidi on television hired three young girls to record an original song about her, complete with techno beats, Chipmunk-style voice distortion and slightly unsettling visuals.