Steamlord

Steamlords command Steambots. They also fix Steambots when ever Samus destroys one with a wave of electrical energy that can also damage Samus if she's in the way. When visible, they are vulnerable to weapon fire. They become invisible while not fixing Steambots.

Three Steamlords are encountered in Corruption. The first Steamlord is featured as a boss and is destroyed by Samus, while the second Steamlord turns on some Steambots to attack Samus, but she can move on and destabilize the bridge they are encountered on, causing them to fall (doing so will earn the player a Friend Voucher).

The third Steamlord is found after the destruction of the Seed on Elysia. Samus is equipped with the Plasma Beam at this point, making for a much easier battle as it will damage the Steambots beyond repair. However, if the player has aquired the X-Ray Visor at this point, it can be used to find the Steamlord while he is invisible.

A Steamlord also appears in an unlockable Diorama in the game's Extras menu.

Logbook entry
Metroid Prime 3: Corruption: "Steamlords command the worker drones of SkyTown. They also repair them when they malfunction or break down. Lightly armored, they rely on their cloaking field to evade their enemies. They can generate localized EMP fields to hinder enemy visor systems."

Trivia

 * The Steamlord's theme, "Steamlord", can be purchased as a bonus feature, allowing the player to listen to the music. The song plays three times: during the first Steamlord battle, during a battle against numerous Tinbots in the Aurora Chamber before Ghor appears and against another Steamlord in the Dynamo Storage area when Samus goes to retrieve the Power Cell.


 * Also there is a glitch that allows the player to listen the Steamlord's theme anytime. After defeating the second Steamlord the player takes the elevator to exit the room (ballista storage), but before leaving the next room, is possible to take the elevator back to ballista storage and listen the theme again.


 * The robot-like creature, with two red "wings" that appears on the Ziplines across Elysia, and attempts to throw Samus away, might be a Steamlord.


 * The Steamlords also created the swarming Steamspiders.


 * The Steamlord's theme is vaguely similar to the music heard when battling the second form of Mother Brain from Super Metroid.


 * This is the Steamlord's theme: http://www.youtube.com/watch?v=HvptQWI29bE&feature=related.