Prior to the events of Anastasia, Bartok used to be an entertainer who travelled through all of Russia with a bear named "Zozi". Bartok and Zozi had to find Prince Ivan, who was allegedly kidnapped by a witch named "Baba Yaga". In order to locate the missing prince, Bartok had to complete three difficult tasks requested by Baba Yaga to prove himself worthy. He had to find someone named Piloff, locate a crown belonging to a heated guardian, and retrieve a floating feather without using his ability to fly. However, Bartok eventually learns that Prince Ivan was never away from the castle in the first place, and finds out that Ludmilla is responsible for his alleged disappearance. Bartok successfully defeated Ludmilla through his wits after she drank his potion, turning her into a hideous dragon. Bartok is finally hailed as a hero by the townspeople, before saying goodbye to Baba Yaga and Piloff.
It is unknown how Bartok and Zozi parted ways, but Bartok did serve a fraudulent priest named Rasputin, who thought he was a holy man. Bartok was sometimes responsible for keeping his reliquary safe, since it was essential for Rasputin to achieve his dark purposes. He tries to get his master to move on, but Rasputin was already consumed by his desire to eliminate the last surviving Romanov, no matter what it took for him to do so. When Rasputin finally confronts Anastasia for the last time in Paris, Bartok switched sides by leaving his master's side. He gets a kiss from another bat at the very end of the movie.
Bartok has received fairly positive reception from most of the fans for his zany, but kind-hearted nature, in spite of not being an extremely popular animated sidekick.
Some fans even enjoy his journey to become a true hero in the spin-off film, "Bartok the Magnificent".