Real name: Kevin MacTaggert and Gilbert Benson
Former aliases: (MacTaggert) Mutant X, (Benson) Piecemeal I
Identity: Secret; the general populace is unaware of Proteus' existence
Occupation: Inapplicable
Legal status: (MacTaggert) Subject of the United Kingdom with no criminal record, (Benson) Unrevealed
Place of birth: (MacTaggert) Unidentified location in Scotland, (Benson) Unrevealed
Marital status: Single
Known relatives: (MacTaggert) Moira MacTaggert (mother), Joseph MacTaggert (father, deceased), Lord Kinross (grandfather); (Benson) Erika Benson (Harness, mother)
Base of operations: Moira MacTaggert's Mutant Research Center, Muir Island, Scotland; Edinburgh, Scotland
Group affiliation: None
First appearance: (voice only) UNCANNY X-MEN #119, (first visual appearance) UNCANNY X-MEN #125, (Piecemeal I) NEW MUTANTS ANNUAL #7, (merger of Proteus and Piecemeal I) UNCANNY X-MEN ANNUAL #15

History: Over twenty years ago Moira MacTaggert was hospitalized for a week after being battered by her abusive husband Joseph MacTaggert, a member of the Royal Marine Commandos. She did not return to him, nor did she tell him that she had become pregnant with his child. Joseph MacTaggert, however, would not grant her a divorce since he believed the prestige of being married to such an important scientist benefited his political ambitions.

Moira gave birth to a son, Kevin, and they lived on Muir Island, where Moira established her research complex, off the coast of Scotland. But when Kevin's dangerous mutant powers emerged, she was forced to imprison him in her Muir Island compound. His continual hunger for energy would have caused him to burn out his own body if not for the energy fields Moira set up in the cell to sustain him. In her effort to keep the fact that she had a son a secret, Moira referred to her captive only as "Mutant X."

For ten years Kevin remained within his cell, his resentment towards his mother growing, even though she continually worked to find a cure for him. Then one day during a battle at the Muir Island compound between Magneto and the X-Men, the vanadium steel walls that kept him prisoner were breached. Kevin was now free of his confinement, but without the energy fields to sustain him, he began to burn out his natural body. Kevin transferred his mind and powers into the body of a local malcontent named Angus MacWhirter. He rewired the equipment in such a way as to fool Moira into believing that Mutant X was still in his cell.

Later, however, Moira entered Mutant X's cell and found her son's shriveled corpse. His current host body was now burning out, and Mutant X needed to take possession of a new host. After failed attempts to take possession of Phoenix and Polaris at Muir Island, Mutant X was able to take control of one of the duplicate bodies of Moira's assistant, Jamie Madrox the Multiple Man.

Mutant X stole body after body as his hosts burned out more rapidly. The X-Men pursued him, and during their first battle Mutant X declared his new name was Proteus, after the shapeshifting god of Greek mythology. Finally, Proteus made his way to Edinburgh, the capital of Scotland, where he seized control of his own father's body. There Proteus waged a tremendous battle against the X-Men in which he used his powers to distort reality throughout the city. His tremendous outpouring of energy destroyed Joseph MacTaggert's body, and Proteus was left as a being of pure energy. Before he could seize a new host form, the X-Man Colossus, knowing that metal could destroy him, smashed his organic steel fists into Proteus's energy form. The resulting explosion dispersed Proteus' energies around the world.

Later, Moira MacTaggert, thinking herself somehow responsible for Proteus's fate, considered cloning him from genetic material in his deceased original body, which she had kept preserved. Sean Cassidy, the Banshee, who was then her lover, dissuaded her from doing so, and she allowed Kevin's body to begin decaying naturally.

Years later, the arms manufacturers known as the Advanced Idea Mechanics, or A.I.M., attempted to recreate Proteus in the following manner. A.I.M. employed a mutant named Erika Benson, alias Harness, to have her young son Gilbert, alias Piecemeal, use his mutant power to absorb Proteus' dispersed energies from different locations around the world. A.I.M. intended to transfer Proteus' energies from Piecemeal into human-shaped body casings created to contain them.

As he absorbed more and more of Proteus' energies, Piecemeal grew tremendously in size, until the boy could no longer contain such tremendous forces. The boy's body exploded, resulting in the creation of a sentient energy being who was an amalgamation of Piecemeal and Proteus.

After his energies had been dispersed years before by Colossus, Proteus's consciousness had found peace in viewing reality in terms of simple mathematical concepts. Now the combined Proteus and Piecemeal sought to regain that sense of peace by transforming everyone and everything in the world into simple geometrical shapes and patterns, beginning with the city of Edinburgh and its citizenry. The New Mutants, New Warriors, the original X-Factor, and an alternate team of X-Men formed by Moira MacTaggert all tried in vain to stop the Proteus/Piecemeal creature.

Finally, convinced that he could not find happiness in the world either by leaving it alone or by transforming it, the amalgamated being returned Edinburgh and its people to normal and vanished. Whether the Proteus/Piecemeal being committed suicide or departed for an unrevealed location remains to be seen.

Height: Inapplicable
Weight: Inapplicable
Eyes: Inapplicable
Hair: Inapplicable
Other distinguishing features: Proteus exists in a pure energy form, although he could take possession of humanoid bodies.

Strength level: Proteus exists in a state of pure psionic energy and hence has no physical powers. When he inhabits a host body he possesses whatever physical strength that body possesses, although his energies rapidly "burn out" the body, weakening him until he can take possession of a new host.

Known superhuman powers: Proteus is a mutant who possesses the vast psionic ability to manipulate and alter reality. Originally Proteus could not use his reality warping powers against another person unless he made visual contact with his victim. However, he apparently did not suffer from this limitation with regard to inanimate objects, since he was able to extend a "reality warp" over much or the entire city of Edinburgh.

Proteus also possesses telepathic abilities. Some of the X-Men have theorized in the past that Proteus merely creates illusions in people's minds that he manipulates reality, but the preponderance of evidence is that Proteus's reality-warping powers are indeed real.

After Proteus's powers "burned out" his original body, he existed in a state of pure psionic energy. He could take possession of a human body as a host, but his energies rapidly "burned out" the body, killing it. His energy form would rapidly disperse unless he took possession of a new host. Proteus' energy form could also be dispersed by metal, even when he occupied a host body. He was also vulnerable to organic metal such as Colossus' body. Dr. MacTaggert once kept Proteus imprisoned within a metal cell, but it has not been explained why Proteus did not simply use his reality-warping powers against her to escape; perhaps the cell's special energy fields somehow prevented him from escaping.

After Proteus and Piecemeal merged, the resulting energy being was no longer vulnerable to metal. Moreover, the amalgamated being apparently no longer needed host bodies in order to survive, nor did it have to see a living victim in order to use his reality-warping powers upon him.