Real name: Unrevealed
Identity: Publicly known
Occupation: Student
Legal status: Presumably a citizen of the United States with no criminal record, still a minor
Place of birth: Presumably New York City
Marital status: Single
Known relatives: Annalee (foster mother, deceased)
Base of operations: (current) Massachusetts Academy, (former) X-Factor headquarters, New York City
Group affiliation: (current) Generation X, (former) Morlocks, X-Terminators
First appearance: X-MEN # 179

History: Little is known of the origin of the mutant known as Leech. He was presumably abandoned by human parents and discovered by the mutant known as Caliban. Caliban took the young Leech with him into the network of tunnels known as the "Alley" running beneath Manhattan which housed the mutant outcasts called Morlocks. There he lived a lonely unhappy existence until the empathetic Annalee adopted him after her own children were shot dead by the Marauder assassin called Scalphunter.

Leech experienced a short-lived happiness as the foster son of Annalee until the enigmatic figure called Mister Sinister sent the Marauders to wipe out the Morlock community. Although various super heroes opposed the Marauders during the so-called “mutant massacre”, Annalee was slain in the melee. Leech, however, was saved by his friends in Power Pack and by the members of X-Factor. X-Factor was searching for their autistic trainee, Artie Maddicks, whose appearance was similar to Leech's own.

Maddicks and Leech became fast friends and X-Factor adopted Leech and began to train him in the use of his power. For a while, Leech and Artie were enrolled at the St. Simon Boarding School, during which time they worked with six other mutants trained by X-Factor calling themselves the X-Terminators, but were kidnapped by demons during the Inferno crisis.

Recently, Leech and Artie Maddicks have been in training with the new mutant team called Generation X.

Height: 4 ft. 2 in.
Weight: 67 lbs.
Eyes: Yellow, no visible pupils or irises
Hair: None
Other distinguishing features: Green Skin

Stength level: Leech possesses the normal human strength of a boy his age, height and build who engages in moderate regular exercise

Known superhuman powers: Leech is a living "power dampener" who causes the cessation of power in other living beings with superhuman abilities, mutant or otherwise. The superhuman powers of such beings cease to function within a certain radius of Leech's whereabouts. Leech has made great strides in controlling this ability and may condense his dampener field within inches of his body with great concentration. The furthest Leech has been able to project this field was up to a radius of 30 feet. It is generally assumed, however, that Leech's control over his power will increase with age.