Zero Suit Samus
Zero Suit Samus (ゼロスーツサムス, Zero Sūtsu Samusu), often abbreviated as ZSS, 0SS or Zamus is Samus Aran without her Power Suit, i.e. with her Zero Suit. The name is taken from Zero Mission, the first game to feature the form fitting suit.
 Character Description
Samus is covered completely from neck to toe in a form fitting blue suit with pink Chozo markings on her back and chest. Her long blonde hair is tied back into a ponytail with a red band. Although quicker and more agile without her suit, she is also less heavily armed, forced to resort to her short-ranged emergency pistol to defend herself. This Paralyzer also has whip-like abilities, known as the Plasma Whip and Plasma Wire (created for Brawl).
Zero Suit Samus first appeared in Metroid: Zero Mission, a remake of the original Metroid for Game Boy Advance. Following the "normal finale" after Samus' defeat of Mother Brain, Samus escapes the base on Planet Zebes. A cutscene immediately follows which shows her shedding her Power Suit in order to fly her original Gunship. However, Space Pirate ships shoot her down back onto Zebes' surface. Stranded and without her Power Suit, Samus must infiltrate a nearby Space Pirate compound and sneak her way into an area where an ancient Chozo Ruins test will grant her a more powerful Power Suit.
Zero Suit Samus appears very briefly during ending sequences for Metroid Prime 2: Echoes and Metroid Prime 3: Corruption. In both of these instances she deactivates her Varia Suit before or while entering her ship, revealing her Zero Suit. There is a brief moment where she looks toward the camera in both games. Also in Corruption, Samus is shown briefly in her Zero Suit during the opening scene before she activates the Varia Suit inside her ship.
Samus also appears in her Zero Suit in early scenes of Metroid: Other M. She also appears in the dying sequence, that is whenever Samus dies, her suit disappears revealing her Zero Suit. Samus also appears without her Power Suit in the cutscenes before her battle against Ridley and before Adam's death. She makes her third playable appearance during the timed escape sequence at the end of Metroid: Other M, where she must escape a ship about to be destroyed. She is also equipped with the Paralyzer here.
 In Super Smash Bros.
A reflection of Samus in her helmet can be seen in her "Congratulations!" screen. Also, when Samus is shot by a Ray Gun or hit by one of Pikachu's electric atacks, a faint outline of a female polygon can be seen, representing her suitless self.
Though Zero Suit Samus did not appear in the game, a special trophy called Samus Unmasked shows Samus with her helmet in her hand. Multiple events in Japan allowed players to obtain the trophies, but no such events occurred elsewhere. The NTSC version still has the trophies in its data, however, and the trophy can be obtained with Action Replay. The trophy has no data in the PAL version, making it completely impossible to obtain.
 Trophy description
It's said that the orphaned Samus Aran was raised by the few survivors of the Chozo race. They armed her with a Power Suit and taught her the ways of advanced combat; even burdened with her heavy suit, Samus is as graceful as a butterfly. In the Metroid series, it was standard that Samus would remove her helmet and armor if you cleared the game fast enough.
Zero Suit Samus is a newcomer in Super Smash Bros. Brawl. Her playstyle has been described by many as being similar to Sheik, in that she possesses many quick and acrobatic moves and transforms from another character. Equipped with a paralyzing laser gun that has the ability to transform into a plasma whip, Zero Suit Samus retains Samus' tether recovery capabilities. She is ranked 9th on the tier list in B tier.
 Trophy Info
Samus Aran without her mighty Power Suit. In this condition, she does not have the firepower she's famed for but is in full possession of the agility and athleticism she gained through her childhood training with the Chozo. Without the armor, she's also much, much faster. The weapon she carries is a self-protection device known as a Paralyzer that stops enemies cold.