Leland possesses the mutant ability to increase the mass of an object or person, making it extremely heavy.

Thanks to his allegiance to Sebastian Shaw, he attained the rank of Black Bishop of the Lords Cardinal of the New York branch of The Hellfire Club, an exclusive secret society bent on world domination.

Created by writer Chris Claremont and artist/co-writer John Byrne, Leland first appeared in The Uncanny X-Men #132 (April 1980).

Leland made subsequent posthumous appearances in Classic X-Men #7 (March 1987), The Sensational She-Hulk #34–35 (Dec. 1991–Jan.

[3] When the Hellfire Club again captures the X-Men weeks later, Leland takes revenge by using his power on Wolverine until his heart gives out, though his rival's death proves to be a temporary state induced by Amanda Sefton.

[5] The supervillain Black Talon revives Leland's body as a zombie,[6] and sets him and other undead mutants (Changeling, Living Diamond, and Scaleface) against She-Hulk.

She defeats them, and Leland is reburied, with precautions are taken to ensure that he never will come back, among them filling his mouth with salt and sewing his lips together.

[9] Harry Leland, among other members of the Hellfire Club, was originally planned to appear in Dark Phoenix, but was ultimately cut from the film.