Zubu and his siblings were abandoned by an unnamed woman who could no longer take care of them. In order to survive, he had to resort to stealing fish and foods from humans while continuing to nurse a grudge against them for their cruelty. He was eventually found by Doraemon and Nobita, soaking in rains outside the Nobi's resident, and was given the name by Nobita based on his appearance. Though was given food and shelter by the two alongside Ichi, Zubu remain distrustful and always went out alone whenever possible.
Eventually, Zubu and the rest were taken by the gang to 300 million years in the past to build their own world without having to fear humans or other animals. He, along with other cats and dogs, eventually evolved thanks to the Evolution Beam and managed to create their own country, with him being one of the influential members of the society. However, Zubu's hatred didn't go away, and he wrote all his past, involvement with a "robot cat from the future", and all his hatred toward human inside the Book of Dark Arts, which eventually passed on to Nekojara, his descendant from thousand years later, and eventually motivating him to succeed in what Zubu wasn't able to.
- The word zubu means drenched in Japanese.
- Zubu is perhaps the only antagonistic character to never engage in a battle against the gang directly, instead, serving as a motivation for the primary antagonist of the movie.
Names in different languages