Sailor Tin Nyanko is the fourth of the Sailor Animamates to appear. Her human pseudonym in the anime is Nyanko Suzu, which is drawn from her Senshi name and from suzu, the Japanese word for both "tin" and "bell." Nyanko is a colloquial term for a cat, drawn from nyan (the Japanese equivalent of meow). Her pseudonym in the English manga is Kitty Bell.

In the manga, Tin Nyanko appears in Act 45 as a new transfer student from Libya. As did Lead Crow, she confronts people from her home planet, Mau—in this case, Luna and Artemis. Diana arrives and tries to protect them, but Tin Nyanko's Galactica Puppet attack transforms all three into their humanoid selves, then injures the crescent moon markings on their foreheads and turns them into ordinary and badly hurt cats. Sailor Star Fighter attacks her, and although she escapes unharmed, she is killed by Galaxia. It is revealed that Sailor Tin Nyanko killed Sailor Mau, the Senshi of her home planet. According to the Materials Collection, Tin Nyanko also has the ability to manipulate scents and supposedly has nine lives.

In the anime, Tin Nyanko appears in Episode 188 as a rival to Sailor Lead Crow and Sailor Aluminum Siren. She is partly responsible for both their deaths, and in the process learns Sailor Moon's identity. During their confrontation, Sailor Moon attempts to heal her, and succeeds only in knocking off one of her bracelets. This allows Nyanko's true personality to partially assert itself; however, she is torn between her duty to kill the Sailor Senshi and a new urge to rebel against her master. Symbolically, it also turns half of her uniform white. Sailor Galaxia resolves the situation in Episode 195 by removing the remaining bracelet. When Tin Nyanko dies, she leaves behind a small golden bell that had been part of her uniform.