Zuzo appears in the special Elena and the Secret of Avalor. When Shuriki seized control of the Kingdom of Avalor following the murder of the king and queen and imprisonment of the surviving members of the royal family, Alacazar, the royal sorcerer, entrusted his chanul Zuzo to send the princess who has the Amulet of Avalor on a journey to free Elena from the amulet so she could free Avalor.
Forty-one years later, Princess Sofia obtains the amulet and travels to Avalor to speak with Zuzo. At Alacazar's old home, Sofia meets Alacazar's grandson Mateo, who helps summon Zuzo from the spirit world. After he is summoned, Zuzo quickly greets them and explains that the only way to free Elena is to place the amulet in the statue of Azaluna with Shuriki's wand. After he finishes his instructions, Zuzo also gives Sofia special advice and he then returns to the spirit world. Sofia understands the meaning behind his words later on when she gets everyone in Avalor to join together and overthrow Shuriki.
Zuzo appears in the show that follows the events of the special. Due to residue magic left over from the Amulet of Avalor after she was freed, Elena is able to see and communicate with Zuzo without having to summon him. In turn, Zuzo is able to offer Elena advice in times of need. Due to his service under Alacazar, Zuzo knows much about the magic of Avalor and so is able to explain Elena's discoveries of her enhanced magic to her.
Zuzo is based on a chanul, and the belief of a Mayan tribe in southern Mexico that everyone has a spirit double in the animal world, such as the Tzotzil.
In "Spirit Monkey Business", it's revealed that Zuzo also acts as the spirit guide for other people and not just Elena.