Sailor Iron Mouse is one of the five Sailor Animamates. In the past, she lived on the planet Chuu and killed the planet's guardian, Sailor Chuu, in order to gain Sailor Galaxia's favor. Described in the Materials' Collection, she is a fast talker with a high-pitched voice, and her death move is Galactica Crunch.
Sailor Iron Mouse is a young girl who is extremely short, at least a foot shorter than most people, with Takeuchi noting in her concept art that she is about Chibiusa's height.
Iron Mouse has short curly white hair, silver eyes and a split upper lip. She has mouse ears on her head, surrounded by yellow beads, and loose hair curls and hangs from her ears. Her accessories - earmuffs, shoulder protectors, gloves, and the top of her boots - are made of or are lined with fine white fur. Iron Mouse's tank top is white as well, with fur on the bottom half, and it is covered in some kind of black ribbon. She wears white stockings and white boots, as well as black bottoms, and her Galactica Bracelets are hidden under the fur on her wrists. To top it all off, she also has a mouse tail.
Iron Mouse briefly appears towards the end of Act 50. She stands in the back of the auditorium where the Three Lights are performing. Overwhelmed with joy that there are ten Sailor Crystals gathered in one place, she attacks the crowd. After the seven Solar System Sailor Senshi transform, Sailor Iron Mouse uses Galactica Crunch, but the attack is countered by Space Turbulence and Submarine Violin Tide. In return, she absorbs the two attacks with her bracelets. Suddenly, Sailor Iron Mouse is abruptly destroyed by three mysterious figures with Star Sensitive Inferno. The bracelets shatter.