Sami the Chimp, who passed away in 1992, is a Belgrade legend. Sami escaped from the zoo twice, and like many chimps, he didn't feel he was a chimp, but rather a human.
He made his first escape in 1988. Radio stations updated live on attempts to capture him, while hundreds of citizens rallied to support Sami in his fight for freedom. You can read more about him here at Belgraded.
In this photo you can see that Sami still manages to entertain visitors to the zoo.