Rebecca Golden was an affluent Jewish debutante who died at the age of 18 when she drowned in a yachting accident. Becky then encountered the otherworldly spirit of water and was resurrected, imbued with the powers of water and sent back to Earth as Fathom to defend it from the evils of the Shadowspear.
Having lead a sheltered and lavish life, Fathom has the hardest time of the Elementals adjusting to their new roles in society and the world. Fathom frequently suffers emotional pain at the rejection from her friends from before her death. Despite the fact that Fathom is the only Elemental to receive any support from pre-death associates, both from her father and her butler, Lawrence, Fathom often seemed the most lonely and least able to cope with the changes in returning from the dead.
Fathom's somewhat carefree upbringing also left her unprepared to wield such tremendous power and shoulder responsibility for the entire world. Though Fathom's powers are capable of creating massive tidal waves that kill hundreds, and flooding an entire subway system killing thousands, Fathom shows the most amount of remorse towards those killed from her actions, reflecting back upon these moments even years later. Though she eventually grows to accept the taking of life for the greater good, she always seems to be the most sensitive member of the Elementals, learning to control her temper and use only minimal force to neutralize without killing. She frequently admonishes her teammates as well for their more lethal methods of dealing out justice.
Of all the Elementals, Fathom maintains the most amount of interest in the goings on of the social world, marketing a line of clothing and frequently doing interviews and autograph signings. In personality, she seems to be the least detached of the Elementals, though it is still noted that she carries the same uncomfortable aura of death that other paranormal's raised from the dead do.
Fathom is composed of living water, able to liquefy at will, generate blasts of rushing water, to travel underwater or within the topside at extremely high-speeds without mechanical assistance, and she is also able to manipulate liquids around her psychokinetically. The volume of liquid which Fathom can manipulate at one given time has proven to be in the tons, amassing enough water in the coastline of Natch Island to cause a mile high Tsunami to come crashing on the Island.
Fathom is also part of the unliving, or undead, and hense is also un-aging. Fatom is also able to heal at a supernatural rate, so far healing from even the worst of physical trauma. She also gives off a strang and subtle vibe to other "living" and not supernatural people, leaving them uneasy around her.