"Black Tom" Cassidy (Thomas Samuel Eamon Cassidy) is a Marvel Comics supervillain, an enemy of the X-Men, and archenemy of Banshee. Created by writer Chris Claremont and artist Dave Cockrum, he first fully appeared in Uncanny X-Men #101 (October 1976). In addition to fighting the X-Men, he has clashed with Deadpool a number of times.

Black Tom is a mutant who can manipulate, bond with and project energy through plant life. He was the black sheep of a prominent Irish family. The X-Man Banshee is his cousin. Tom secretly raised Banshee’s daughter Siryn, of whose existence Banshee was unaware, and conscripted her into his criminal gang. Black Tom was also a longtime partner of the super-strong villain Juggernaut, until Juggernaut's recent reformation.

Fictional character biography