Sailor Iron Mouse was the first of the Sailor Animamates to show up. Her human cover identity is Chuuko Nezu—a name that works as a clever pun, since "chuu" mimics the sound mice make and "nezu" literally means mouse. She lives up to the name in more ways than one: she's noticeably short, standing at least a foot below most people she targets. According to Takeuchi's notes, she's roughly Chibiusa's height, though the anime doesn't quite commit to that. True to being a mouse, she's terrified of cats.
In the manga, Iron Mouse barely gets a story. She appears for just a few pages in Act 43 during a concert at the Fantastic Music Hall featuring the Three Lights and Michiru Kaioh. She attacks using "Galactica Crunch" before being killed by Sailor Star Healer. We later learn she's responsible for taking out Sailor Chuu, the senshi of her home planet.
The anime gives her much more room to breathe. She's got this mix of childlike enthusiasm and real intensity—she tends to go after famous or impressive targets and seems to genuinely enjoy the work. That said, she's visibly scared of Galaxia. Iron Mouse can teleport using a phone booth she summons, and she can use it defensively too. She sticks around as an antagonist for several episodes, but in episode 181, Galaxia kills her for failing to collect enough starseeds. This happens even though Iron Mouse had actually managed to figure out Sailor Star Fighter's identity, which makes her death feel like more of a punishment for weakness than actual failure.
Content compiled by AnimeList.moe from publicly available sources.
