Cross-Dressing Voices: Zach in the first two seasons. For the rest of the series starting with season two's second half, he was voiced by a boy.
Hey, It's That Voice!: The animals are voiced by the voice actors mentioned in the main page's description.
Not to mention, the characters in the story segments are voiced by professional actors (see Sesame Street Cred on the main article).
Keep Circulating the Tapes: In the 2000s, the first 26 episodes were redubbed in Singapore because it was too expensive to keep paying royalties to the celebrity voices. These are the versions available on DVD, qubo, and BYUtv. Because TV reruns and DVDs of the series are nothing more than the Singapore dubbed versions, the original PBS versions are easier to find on either official VHS releases by PBS Home Video and later Chik-Fil-A or tape recordings of the old airings. Strangely enough, the official KidMango/YouTube versions of season 1 have the original voices (although "Loyalty" was never uploaded). Season 2 is harder to find, because the VHS tapes were only available to schools, libraries, churches and other institutions, and fewer and fewer of these still have VHS. (Season 3 was never redubbed, because the voices were done in Vancouver, not Hollywood, so there's no celebrity VAs to pay royalties to.)
Network to the Rescue: The show was saved by Bruce D. Johnson and backed through his startup production company, PorchLight Entertainment, because he loved the original book.