She is the monster behind the Foe's plans for world domination by exterminating Earth's two dominant life forms: Humans of the land and Dolphins of the oceans who have lived together in peace and friendship for 500 years.
The Foe were a violent alien race that had a strong desire for conquest, tearing everything that stood in their path apart. At some point, the Foe came across the planet Earth and discovered the planet's two dominant life forms: Humans who ruled Earth's land, and Dolphins who ruled Earth's oceans. The two races lived together in peace for 500 years. The Foe Queen declared war on Earth and the Foe attacked Earth intending to destroy both Humans and Dolphins as well as take over Earth. Ultimately, fights broke out all over the once peaceful planet.
After a long time of conflict between Earth's inhabitants and the invading Foe, Humans and Dolphins eventually defeated the evil alien invaders and drove the Foe away from Earth and the Foe Queen swore revenge on Earth's dominant life forms. Years later, the Foe returned to Earth with intentions yet again to conquer Earth to get revenge for their previous defeat. However, the Humans and the Dolphins had created a tall crystalline figure called the Guardian which protected Earth by projecting a force field around the planet. The Foe, however, did not give up, and made repeated suicide crashes into the force field in search of the Guardian's weak spot. Later, a small Foe spacecraft crashed into the Guardian's weak spot, shattering the Guardian and disabling the force field in the impact. With Earth defenseless from incoming Foe vessels, the Foe slowly began their descent to Earth. However, a young dolphin named Ecco traveled to the dolphin city of Atlantis and repaired the Guardian, but was too late to stop the Foe from reaching Earth.
Upon arrival, a large Foe warship used a vortex to rob the Dolphins of their five traits: Intelligence, Ambition, Compassion, Wisdom, and Humility. Ecco, realizing what the Foe were doing, dashed into the vortex after the five traits. With the five traits missing, the Foe altered Earth's history into a nightmarish world where Dolphins were weak and gullible and Humans had been extinct for unknown reasons. After Ecco recovered Intelligence, he figured out the truth behind the extinction of the Human race: When the Foe invaded Earth, the Humans created a powerful superweapon called the Engine of Salvation, but the Humans and the Foe destroyed each other before the weapon was completed. Before the Engine of Salvation could activate and render Dolphins extinct, Ecco quickly traveled inside the machine and destroyed the core, and ultimately destroyed the Engine of Salvation as a result.
After destroying the Engine of Salvation, Ecco recovered Ambition and time altered a second time into another nightmarish world where Dolphins became agressive and drove Humans into exile. These Dolphins then organized themselves into a warlike Clan while the remaining peaceful Dolphins became Outcasts. After rescuing the leader of a secret Outcast Resistance from the Clan, Ecco discovered that the Outcast Resistance has been in possession of Compassion and the Clan was in possession of Wisdom and captured the leader because they wanted Compassion for themselves. After recovering Compassion, Ecco went through the hanging waters and confronted the Exalted Ones, who were the leaders of the Clan. The third Exalted One named Mutaclone had been in possession of Wisdom. Ecco defeated Mutaclone and recovered Wisdom which caused Earth to warp into a dark world which the Foe ruled over as their domain and the Foe Queen came into posssson with the final trait: Humility.
Upon entering the Foe's dark world, the Foe Queen and her minions instantly attacked Ecco, but Ecco fought off the Foe and faced the Foe Queen himself, which ended with the heroic Dolphin blinding the Foe Queen in both eyes. Ecco immediately made his way to the Foe Hatchery and destroyed it. In a last hitch effort to recover Humility, Ecco entered the Foe Queen's body through a wound and used his sonar shockwaves to destroy the Foe Queen's heart, killing the Foe Queen and giving Ecco enough time to escape and return to the restored present, taking Humility with him as the dark world was engulfed in a flash of light and seemingly destroyed the Foe once and for all. With all five traits recovered, Humans and Dolphins were complete again and the Dolphins made a silver statue of Ecco in Atlantis to honor Ecco's heroic quest. It is unknown if the Foe were destroyed along with their queen, but considering it was their homeworld, it is highly possible.