The Amazoness Quartet (アマゾネス カルテット, Amazonesu Karutetto?) consists of CereCere, PallaPalla, JunJun, and VesVes. Their attacks are derived from circus skills, with each having a specific talent. In the English-dubbed anime, they are called the Amazon Quartet. In order to remove a person's Dream Mirror, a member of the Quartet hits her Amazon Stone with a pool cue, similar to a billiard ball. The mirror is knocked out of the person the instant it makes contact with them. They also use the Amazon Stones for other attacks. In the manga, they also created and commanded the Amazon Trio to attack the Sailor Senshi, whereas in the anime the Trio came before the Quartet and served Zirconia.
In the manga, they are actually the Sailor Quartet—commonly referred to in English-speaking fandom as the Asteroid Senshi, because they are named after the first four major asteroids to be discovered. The four asteroids hold particular importance because they were originally considered planets in history before more were discovered.
They had been placed in a deep sleep somewhere within the Amazon Jungle, awaiting the time when they could become the future protectors of Sailor Chibi Moon, analogous to Princess Serenity's four soldiers (the Guardian Senshi) and to Prince Endymion's four generals (the Shitennou). However, Queen Nehelenia woke them prematurely and forced them to work for her. At her defeat, they are returned to their true forms by Usagi (in the form of Neo-Queen Serentiy) and to their long sleep. During the fifth story arc, they accompany Sailor Chibi Moon from the future to help in the fight against Sailor Galaxia. The Sailor Quartet's uniforms are a cross between those worn by the Sailor Team in their first forms and their final forms, with the Quartet's own image colors. The uniforms have one-layer skirts, belts, chokers and back-bows like those on the Sailor Team's first uniforms, with boots, gloves, brooches, leotards, and tiaras the same as the final forms. Their shoulder pads are in the style of the final uniforms, but are white. They are shown using 2 attacks as a group, Pink Lady's Freezing Kiss (all four of them plus Sailor Chibi Moon) and Amazoness! Jungle Arrow (used by the four Quartet members).
In the anime, the Quartet's history of being former sailor senshi's were never shown to viewer and the story is followed after they are captured by Queen Nehelenia and is already a part of her Dead Moon Circus. They began working for Queen Nehelenia after Queen Nehelenia decided to appeared inside a magical mirror after hearing the Amazoness Quartet playing in a forest, and then offered to keep the Amazoness Quartet from ever growing old in return. She changed their dreams into the physical form of Amazon Stones, instructing them to use these to remove the "dream mirrors" of humans. They are dedicated to this task, but still generally spend more time playing than working. The Amazoness Quartet, being children, wished to ride Pegasus and seeing that Pegasus can only be called by Chibiusa, decided to secretly free Chibiusa from Queen Nehelenia's captivity by creating a replica rag doll of Chibiusa and swapping the real Chibiusa with the replicate rag doll. After Queen Nehelenia found out about the rag doll trick, the Amazoness Quartet were imprisoned inside mirrors in another dimension by Queen Nehelenia as a result. During the battle between Zirconia and the Sailor Senshi group, they were released by Queen Nehelenia at Zirconia's bidding in an effort help Zirconia fight the Sailor Senshi. However, Zirconia decided to trap and drain their powers instead to aid herself fight the Sailor Senshi. Sailor Moon then decided to try and save the Amazoness Quartet lives, but in the process could not break free Zirconia's trap. Sailor Moon convinced the Amazoness Quartet to break their Amazoness stones and give up their eternal childhood powers by saying that they can still have children's dreams whilst in adult form, and this was the only way to help break themselves free of Zirconia's control or else they may die from Zirconia's power drain. The Amazoness Quartet each breaks their own stones, and in an act of kindness in return for Sailor Moon having convinced them and saved them from Zirconia control, they then decided to help Sailor Moon fight Zirconia by switching the Golden Cyrstal in Queen Nehelenia's hand with a pineapple, and then giving this Golden Crystal to Sailor Moon to enhance Sailor Moon's powers and hence defeat Zirconia. They parted their ways with the Sailor Senshi, noting that it is possible that destiny will have them meet the Sailors again, as this is consistent with the manga storyline of them becoming Chibiusa's future Sailor Senshi protectors, even though they never showed up again in the next season - Sailor Stars.
The Quartet appears in several of the stage musicals, with a substantially different background. Here they are homonculi created by Professor Tomoe, and are known as the Sammael Quartet. They are portrayed as young children around Chibiusa's apparent age, instead of their normal ages. They are created from Chibiusa's starseed, and are linked to her, having the power to transform into Sailor Senshi as a result.
Read more about this topic: Dead Moon Circus