Voldrums are small, ground-based combat robots created by the Alimbic race to protect their facilities in the Tetra Galaxy. Multiple variants of the design exist, as well as several related mechanoids - the Ice, Magma, and Electro Voldrums. Some variety of Voldrum can be found in every facility in the Alimbic Cluster, with the exception of the Oubliette. All models share the same basic design- a spherical body with a treaded omnidirectional wheel occupying the lower hemisphere. All varieties of conventional Voldrum are vulnerable to all weapon types, although this is not true of the variant models. Voldrums are almost never found travelling independently- they are deployed from "enemy spawners" when Samus approaches or triggers another security system, usually one or two at a time. The only free-roaming Voldrums can be found in the Frost Labyrinth on Arcterra.
All models of Voldrum have spherical bodies, and move around via a treaded, omni-directional wheel. They have no visible sensory receptors. Most models are equipped with twin projectile weapons mounted on their sides, though the nature of said weaponry varies from model to model, as does the durability of their bodies.
This is the only variety of Voldrum that does not possess any sort of ranged weapon, and can only attack by charging directly at threats. However, they emit a shrieking noise and begin to wobble before doing so, making this strike relatively easy to evade. Melee Voldrums are only encountered twice: In the lower level of the Elder Passage on Alinos, and in the aforementioned Frost Labyrinth. Once the pair of spawners that release them in the Passage are destroyed, they never appear there again.
The standard variety of Voldrum, this mechanoid is physically identical to its melee counterpart, except it possesses two guns capable of firing short double-bursts of energy. These Voldrums can be found in the upper levels of the Celestial Archives, and on Arcterra. Its body is a dull blue-grey, with a bright red wheel.
Heavy Voldrums are a tougher, more aggressive Voldrum model found deep within the Celestial Archives and Vesper Defense Outpost. They possess a dull orange wheel section as opposed to the red of the basic Voldrum, and fire a spray of energy identical to that produced by the Alimbic Turret v1.4. Although they use a "rapid-fire" weapon similar to the Battlehammer, heavy Voldrums are not appreciably vulnerable to the Volt Driver, and yield the same scan as the standard and melee Voldrum models.
The Magma Voldrum is rust-colored with a blue wheel, and fires magma-based projectiles vaguely resembling a charged affinity Magmaul shot from each gun, although these follow a linear trajectory and use a different animation. Like Spire and other users of superheated weaponry, Magma Voldrums are immune to heat-based attacks, but can be destroyed easily by the Judicator. All other weapons deal moderate damage. These are encountered in many areas on Alinos (such as Alinos Perch), and once in the Stasis Bunker of the Vesper Defense Outpost.
Electro Voldrums are encountered only once, in the Incubation Vault 02 room on the upper levels of the Celestial Archives. They are dull yellow in color, with a bright purple wheel. Their weapons fire a pair of electrical projectiles resembling charged affinity Volt Driver blasts, which distort the vision of targets (including the Combat Visor), although these projectiles do not home in on targets or explode on impact. Like Kanden and other users of electrical weaponry, the Electro Voldrum is immune to all variants of its own weapons system, but its weaker plating renders it vulnerable to the Battlehammer and other heavy-duty attacks. Other weapons deal moderate damage.
The most recent version of the robot, the Ice Voldrum has a dark purple body, with a bright blue omnidirectional wheel. Its weaponry fires a projectile resembling an uncharged Judicator shot, although it is still capable of freezing a target in its tracks. Like Noxus and other users of subzero weaponry, the Ice Voldrum is immune to all variants of its own weapons system, but extremely vulnerable to the Magmaul and other high-temperature weapons. These are encountered in a passage of the Stasis Bunker, and briefly in the Council Chamber on Alinos.
Metroid Prime Hunters
A high-speed rolling robot in nearly constant motion. Equipped with two large guns for attacking from a distance, it is equally efficient at close-quarters combat.
Metroid Prime Hunters
Another modification of Voldrum technology. Its high operating temperature causes reduced defensive capability against subzero weaponry.
Metroid Prime Hunters
This version of the VOLDRUM has a weaker hull than the standard model, rendering it vulnerable to rapid-fire weaponry.