Metroid Prime also known as The Worm or Dark Samus is a disgustingly mutated Metroid living in the depths of Tallon IV, is able to produce Phazon, and serves as the final boss of Metroid Prime as well as the main antagonist of the whole Metroid Prime series.
Dark Samus is the end result of its unstable mutation coupled with Samus Aran's DNA and her Phazon Suit. Even if Dark samus is an entirely different being physically, her consiousness is the same as Metroid Prime and she retain some of the features she used to have as a Metroid under her armor which acts as her new exoskeleton.
Before the event of the games
A Chozo prophecy foretold that their adopted world of Tallon IV would become infested by a great evil, known to them as the Worm. Some time later the prophecy became true and a Leviathan from the planet Phaaze crashed onto Tallon IV and released Phazon, a highly poisonous and mutagenic substance which poluted the planet. At some point, the "Worm" foretold by the Chozo also came into being when a lone Metroid of unknown origin took up residence inside the Leviathan and began to thrive on its Phazon, mutating beyond recognition and gaining something close to if not sentience. The worm was then sealed inside the Impact Crater by the Chozos who died some time afterward.
Decades after the last Chozo on the planet had died out, the Space Pirates discovered Tallon IV, and became obsessed with the mutagenic properties of Phazon. The Pirates established multiple research facilities on the planet, and began importing Metroids for use in their experiments. They were never able to break the cipher sealing off the Impact Crater but detected the life signs of a massive entity within absorbing enormous quantities of Phazon directly from the Phazon core.
After arriving on Tallon IV, Samus Aran finally broke the seal and faced Metroid Prime who was encased in a black shell. After the shell was defeated, Metroid Prime fell to a lower level, and the pink, tentacled blob that was the creature itself came out of the shell and fought Samus. Before it died, it stole Samus's Phazon Suit containing some of her DNA and exploded. After Samus left the planet, a bubbling pit of Phazon was left, and a black claw shot outwards, a claw with an eyeball in it's back. This hinted at the fact that Metroid Prime fused with the Phazon Suit and reconstructed its body based on the genetic data it obtained from the hunter turning itself into some sort of distorted phazon clone of Samus known as Dark Samus.
Metroid Prime 2: Echoes
In Metroid Prime 2: Echoes, Metroid Prime's new form is officially introduced. Dark Samus arrived on Aether Fifty years after a Leviathan from Phaaze had landed on the planet, ripping open a second, darker dimension, Dark Aether. Dark Samus then roamed the two dimensions to find more and more phazon to feed upon until Samus arrived on the planet and confronted her. Dark Samus is fought three time and serves as the final boss for this game, after her defeat she disappear but is not killed for good.
Metroid Prime 3: Corruption
In Metroid Prime 3: Corruption, Dark Samus returns as the mastermind behind the spreading of Phazon across the universe. She raided the G.F.S. Valhalla to obtain the Aurora Unit 313 and implent it into Phaaze, which would allow her to take control of the planet and all of its assets. She then brainwased the Space Pirates to become her servants. After that she confronted Samus, Rundas, Ghor and Gandrayda on Norion and corrupted them with Phazon, which would in time turn them into brainwashed servants too. However, Samus manage to fight the corruption back, kill the three other hunters and defeat Dark Samus, the Aurora Unit and Phaaze, finally ending the Metroid Prime threat.
Metroid Prime (Exo)
"The aberration known as Metroid Prime is the source of Phazon, making it immensely powerful. A genetic flaw makes it susceptible to certain weapons for brief periods. Only its head is truly vulnerable: other attacks are a nuisance. Offensively, Metroid Prime has a number of natural and mechanical weapons at its disposal. These include Ultrafrigid Beam, Multi-Missiles, Snare Beams, and Particle Wave Projectors. Its massive strength and barbed carapace make it lethal in melee combat. Recommend maximum firepower when engaging this enemy."
Metroid Prime (Core)
"Scans indicate that the Phazon energy form of Metroid Prime is invulnerable to all conventional weapons: only attacks from a Phazon-fused Arm Cannon will damage it. It generates pools of Phazon when it attacks: use these to fuel your Suit’s Phazon weapon system. The entity can also spawn Metroids to assist it in battle, rendering itself invisible when it does so."
Super Smash Bros. series
Super Smash Bros. Brawl
Both forms of the Metroid Prime are featured as trophies in Super Smash Bros. Brawl.
Metroid Prime (Exo)
"The form of the Metroid Prime that Samus first encounters. It can become invulnerable to all but one of Samus's weapons at a time. The body color alternates between yellow, purple, white, and red, with color indicating the weapon that can deal damage. After taking a certain amount of damage, the Metroid Prime exoskeleton reveals its core essence."
Metroid Prime (Core)
"The core form of Metroid Prime after losing its exoskeleton. It can make itself invisible for a set time, which requires Samus to make a visor change. Normal hits do not have any effect on it—the Metroid Prime can eventually be defeated by using the Phazon Beam while standing in a Phazon puddle."
Super Smash Bros. for Nintendo 3DS and Wii U
Super Smash Bros. Ultimate
Metroid Prime as Dark Samus becomes a playable character in Super Smash Bros. Ultimate. Dark samus in an Echo Fighter of Samus and retain most of her attacks who now are Phazon based variants to fit with Dark Samus' usual aesthetic.
- Metroid Prime is the namesake for the entire Prime series