Sailor Aluminum Siren is the second Sailor Animamate to make an appearance. In the anime, her human alias is Reiko Aya, which could be a play on words related to "puppet," "mermaid," "makeup," and "child spirit."
In the manga, Aluminum Siren first shows up in Act 44 on the rooftop of Juuban High School, attacking Usagi and Seiya with Galactica Tsunami. She manages to steal the starseeds of Sailor Mercury and Sailor Jupiter, resulting in their deaths, but she is ultimately killed by Sailor Star Maker and Sailor Star Fighter. Aluminum Siren earned Galaxia's favor by stealing the starseed of her home planet's Senshi, Sailor Mermaid. According to the Materials Collection, her hobby is singing ballads.
In the anime, Aluminum Siren makes her debut in Episode 182. Off-duty, she is polite, somewhat scatterbrained, and constantly eating or feeling hungry. However, once battle begins, she sheds these traits and becomes utterly ruthless. Under the guise of Aya Reiko, she collaborates with Karasuma Akane, also known as Sailor Lead Crow, who reveals that they were once rivals for the top position among the Animamates. Eventually, she discovers Sailor Moon's true identity and nearly succeeds in killing her, only to be thwarted by the Guardian Senshi and the Sailor Starlights. Despite uncovering their identities, Aluminum Siren is killed by Galaxia in Episode 188 for failing to defeat Sailor Moon. She is the only Animamate to use her manga attack, Galactica Tsunami, in the anime, though it involves hurling nearby water bottles, juice boxes, soda cans, and similar items at the Senshi.
