The opossum became a German media sensation after her picture was published in late 2010 and had more than 330,000 fans on Facebook!
Heidi and her sister were found as orphans and raised in a wild animal sanctuary in North Carolina before moving in 2008 to Leipzig Zoo in Germany.
The zoo today released a statement saying: "Heidi, our cross-eyes opossum, has closed her eyes forever".
Rest in peace, Heidi.
-DS