Pirate Homeworld

The Pirate Homeworld is a homeworld of the Space Pirates. Originally thought to be the birthplace of all existing Pirates, the Metroid Prime Trilogy art booklet stated that it is one of the Space Pirate homeworlds. Samus Aran visits the planet in Metroid Prime 3: Corruption. Though the planet is effectively unnamed in the other versions of Corruption, the Japanese version and unused text suggests the planet is named Urtraghus.

Complete Map of the Pirate Homeworld : 

Features
The Pirate Homeworld is plagued by a steady stream of Acid Rain, harming any creature without proper protection. The planet was the first target chosen by Dark Samus to impact a Leviathan on after taking control of Phaaze with AU 313. Space Pirate Data insinuates this occured long before Bryyo and Elysia were impacted. Thus, the Phazon corruption seen on the Homeworld is more advanced than the latter planets, containing many immense Phazon growths on its surface. The Space Pirates' willing interactions with the Seed are likely to have contributed to the corruption as well. The Homeworld was also protected by a gigantic shield, which Samus had to deactivate in order for the Federation's assault to commence. When the Leviathan was destroyed, the planet's corruption was stopped.

Areas
The planet includes the Command Center, a Research Facility, a Mining Site and the Pirate Homeworld Leviathan. In the Command Courtyard, there are three doors in one room that cannot be opened. It is likely that these doors lead to the Pirate's living quarters. Various large tunnels are present too, possibly allowing Pirate Cargo Drones access to the rest of the base. Samus was able to navigate these tunnels using her Gunship, allowing her to move between the sections of the facility quickly and undetected.

Notable Rooms
Command Research Mines
 * Landing Site Bravo
 * Command Courtyard
 * Command Station
 * Transit Station Leviathan
 * Landing Site Alpha
 * Scrapvault
 * Metroid Processing
 * Proving Grounds
 * Landing Site Charlie
 * Phazon Quarry
 * Phazon Harvesting
 * Main Cavern

Biology
While the planet's most abundant life-forms are Space Pirates, Phazon Metroids and a few other bioforms dwell on the planet as well, such as Shriekbats and Scritters, who thrive in the sheltered areas throughout the Space Pirate complexes, despite the inhospitable weather conditions. Another species that may originate here are the Korakk Beasts. A possible plant that may have grown on the planet is the highly toxic Bajar Grove, since it and the pirates are stated as having alkaloid in their systems. A number of mechanical creatures also reside on the planet, like the Puffer Mines which have been cybernetically enhanced to survive the rough conditions.

A number of deceased wildlife can be found and scanned in various places where Pirate experiments have gone wrong, such as in the Scrapvault, where one such example has been woven into the Pirate structure.

The Bounty Hunter Gandrayda also makes an appearance here in a boss battle. The Leviathan on the planet is guarded by Omega Ridley, an enhanced and revived version of Meta Ridley corrupted by Phazon.

Below is a full list of known inhabitants, including creatures, Pirates, and mechanoids.
 * Advanced Aerotrooper
 * Armored Aerotrooper
 * Assault Aerotrooper
 * Berserker Knight
 * Crawlmine
 * Crawltank
 * Dark Samus
 * Demolition Trooper
 * Despair-Class Turret
 * Dread-Class Turret (unseen)
 * Federation Marine
 * "Jolly Roger" Drone
 * Jumpmine
 * Leviathan
 * Liquid Phazon
 * Massive Tentacle
 * Metroid Egg
 * Mining Cannon
 * Omega Ridley
 * Parasitic fungus
 * PED Marine
 * Phaazoid
 * Phazon Grub
 * Phazon Harvester Drone
 * Phazon Metroid
 * Pirate Aerotrooper
 * Pirate Cargo Drone
 * Pirate Commander
 * Pirate Commando
 * Pirate Militia
 * Pirate Surveillance Drone
 * Red Phaazoid
 * Remorse-Class Turret
 * Scarp (deceased)
 * Scritter
 * Shriekbat
 * Space Pirate
 * Tentacle
 * UAM 3
 * ULF 12
 * ULF 16
 * ULF 17
 * ULF 41

Bosses

 * Gandrayda
 * Metroid Hatcher
 * Pirate Commander
 * Omega Ridley

Major Upgrades

 * X-Ray Visor
 * Grapple Voltage
 * Hazard Suit
 * Nova Beam
 * Hyper Grapple

Trivia

 * The Pirate Homeworld is referred to as "Planet Urtraghus" (惑星ウルトラガス) in the Japanese version of the game, although this particular name is not found anywhere in the English versions except in unused logbook entries found within the game's data. A possible reference to this name is the Urtragian Shriekbat that is found upon the planet.
 * According to Aurora Unit 242, the Pirate Homeworld may have become a secondary Planet Phaaze due to the fact it was so corrupted in Phazon that the entire planet was transforming into it as well.
 * There is a glitch in the room Mine Lift that will not let a player continue the game if the player saves after the glitch, forcing them to restart the game. There are two spinners in the room, which cause the lift in the room to drop. However, if one spinner is activated and the player leaves the room, both spinners will be deactivated when the player returns, and the mine lift cannot be dropped. If this happens and the player saves, the game cannot be continued.
 * There is a reference to a seemingly lost Metroid game in the Research Facility of Pirate Homeworld. In the room Metroid Processing, a terminal mentions that "Metroid project 'Dread' is nearing completion." This is often thought to refer to the Nintendo DS video game, Metroid Dread, that seemingly fell off the radar for development; however, the terminal next to it says the project has failed. According to developers at Retro Studios, the reference was not intentional, but this line has caused much frustration and false hope amongst gamers, as Metroid Dread was thought to have been possibly canceled prior to the release of Metroid Prime 3.
 * The theme of the Space Pirate Homeworld is a remix of the music heard while exploring the underground sections of Crateria in Super Metroid. The song was again heard while in Chozodia during Metroid Zero Mission whenever Zero Suit Samus is spotted by Pirates and security systems when trying to regain her lost Power Suit.
 * This is the planet with the most Energy Cells in the game: three in total.
 * The art booklet that is included with Metroid Prime Trilogy refers to the planet as "one of the Space Pirate homeworlds". Like Zebes, both planets were considered by the Pirates as the homeworld: the Space Pirates on Zebes refered to themselves as Zebesians after conquering it, and the Space Pirate logs refer to the planet visited in Metroid Prime 3 as '[their] Homeworld'.
 * The downloadable Doctor Who Game "City of the Daleks" features the Dalek city of Kaalan, a large base on the Dalek homeworld of Skaro. The planet shares many similarities with the Pirate Homeworld, such as acid rain, complete lack of flora or fauna other than the dominant species, and a scarlet hue.