Pirate Trooper

Pirate Troopers are a common variety of Space Pirate first introduced in Metroid Prime 2: Echoes.

In Echoes
During the events of Metroid Prime 2: Echoes, Pirate Trooper's arsenal include a photonic power scythe and quantum assault cannon, which at the time were standard-issue weapons for their rank. Most troopers were stationed at their base in Agon Wastes, which was constantly targeted by shadowy creatures, who took a liking to the pirates' technology and moved to take every trooper they could.

Pirate Troopers appear in other areas around Aether besides Agon, but aren't very common and rarely respawn.

Dark Pirate Troopers are Darkling-possessed Pirate troopers. They are a useful addition to the Ing Horde, as those who are trained to follow orders without question are easier possession targets. They're often placed in locations important to the Ing, such as Dark Portals. Ing also tend to target Pirate Commandos for possession, a unit which they greatly prize.

In Corruption
During the events of Metroid Prime 3: Corruption, Pirate Troopers got a major overhaul, using a new Phazon enhancement system. Their Phazon-powered weapons include an assault rifle and deployable energy scythe, along with EMP grenades for power-armored foes and a new Dash Jet system for increased mobility.

Corruption's basic Pirate Troopers mostly appeared on Bryyo, but they are seen every time the armor of an upgraded Trooper is broken off, implying that the Troopers from Echoes were armored too. They also appeared alongside Militia and Aerotrooper Units on Norion, and also frequently on the Pirate Homeworld.

The Troopers in this game seemed slightly less agile than before, but they could still jump very high. They were not seen to be able to cling to walls either, like the previous incarnations could.

Pirate Trooper Varieties
Several types of Troopers exist in Corruption. Some of these units carry a portable battle shield that can either be removed with the Grapple Lasso or destroyed with Phazon attacks. The Grapple Voltage can also drain or overload energy from or into a Shield Trooper. However this can not be done in one go, as the Pirate will occasionally break free of the lasso. All of these varieties appear as Aerotroopers as well (excluding shield varieties).

Armored Pirate Trooper
Armored Pirate Troopers are equip with a standard armorsuit that provides adequate protection against beam weapons, but can be breached with missiles. These units greatly resemble the Pirate Troopers found in Echoes. Interestingly, while the heart-like feature in Echoes was a deep red, the one in this game is a light blue, to represent the Phazon corruption all the troopers bear.

Assault Pirate Trooper
Assault Pirate Troopers represent the best of the Pirate Troopers in the Space Pirate military. They are equipped with sloped, translucent orange, Missile-resistant armor. A Dash Jet system is also built into the armor. Basic armament includes assault rifles, energy scythes, and EMP grenades, all powered by Phazon. However beams can damage their armor.

Advanced Pirate Trooper
Advanced Pirate Troopers are Pirate Troopers which have been outfitted with a green Phazite armor. The armor is weak against Missile blasts, and resistant to beam attacks. They are essentially stronger versions of Armored Pirate Troopers. Advanced Troopers also have a dash jet system, like many of the Pirate armor systems. Their weapon systems include assault rifles, energy scythes, and EMP grenades. These are the rarest troopers in the game, but are seen mostly during the Federation's assault on the Skyway to the Leviathan.

Logbook entry
Metroid Prime 3: Corruption: "The Space Pirate military forces continue to use Phazon, including a new Phazon enhancement system. Basic armament includes an assault rifle and energy scythe, both powered by Phazon. EMP grenades are often employed against power-armored foes. A new Dash Jet system provides increased mobility."

Metroid Prime 3: Corruption: "The Space Pirates have developed a man-portable battle shield that is resistant to most small-arms fire. Its portability is its weakness, however. Remove it from the pirate's grip to eliminate its primary defense system. Phazon-based attacks are capable of destroying the shield."

Metroid Prime 3: Corruption: "Armored Pirate Troopers are equipped with a standard armorsuit. It provides adequate protection against Beam attacks but is vulnerable to explosive blasts. They are outfitted with all the basic pirate armaments. This includes the assault rifle and energy scythe, both powered by Phazon. EMP grenades are often employed against power-armored foes. A new Dash Jet system provides increased mobility."

Metroid Prime 3: Corruption: "Advanced Pirate Troopers wear an additional layer of ablative armor. Explosive attacks are recommended to break the armor away. Basic armament includes an assault rifle and energy scythe, both powered by Phazon. EMP grenades are often employed against power-armored foes. A new Dash Jet system provides increased mobility."

Metroid Prime 3: Corruption: "The Assault Pirate Troopers are some of the best the pirate military has to offer. They are heavily armored and are resistant to most attacks. Their unique armor will deflect all Missile fire, but is still damaged by Beam attacks. Basic armament includes an assault rifle and energy scythe, both powered by Phazon. EMP grenades are often employed against power-armored foes. A new Dash Jet system provides increased mobility."

Metroid Prime 3: Corruption: "Assault Shield Troopers are heavily armored and resistant to most weapon systems. Their unique armor will deflect Missile attacks, but not Beam fire. In addition to their armor, they wield a portable battle shield. Their battle shield provides protection against all standard weapon fire, but can be easily torn off. Phazon-based weapons are capable of destroying the shield."

Trivia

 * A possible Pirate Trooper is shown fighting Samus in the startup video at the beginning of Metroid Prime Hunters, although there are no Space Pirates in the game, besides the Bounty Hunter Weavel. This may suggest that Samus encountered them shortly before Echoes, due to the fact that Hunters is set between Metroid Prime and Metroid Prime 2: Echoes.