In season 4, Henry Creel is given the Dungeons & Dragons villain name Vecna. Dustin Henderson and Eddie Munson choose the name because Henry's supernatural murders resemble the powerful undead wizard from the game.
Henry was formerly known as Number One, the first child studied by Dr. Martin Brenner at Hawkins National Laboratory. After Eleven overpowers him, she banishes him to the alternate dimension. There, his body is transformed by the environment, and he becomes the scarred figure known as Vecna.
The name is a deliberate Dungeons & Dragons reference rather than Henry's original identity. In the role-playing game, Vecna is an ancient lich associated with dark magic, undeath, and manipulation. Eddie, an experienced Dungeon Master, uses the game’s mythology to help explain the creature’s powers and likely behavior.
The show’s Vecna and the game’s Vecna are not literally the same character. The television series borrows the name and some thematic traits while making Henry the mastermind behind the supernatural terror haunting Hawkins.