In the past "X-Men" films, James McAvoy's character Professor Charles Xavier, better known simply as Professor X has noticeably thick hair, but in the comic books, his character is known for being bald.

In "X-Men: Apocalypse," moviegoers will finally witness Professor X lose his hair, and McAvoy recently shared during an episode of "The Graham Norton Show" just how this happens.

"He ends up going through something so horrible and painful that he literally half pulls his hair out half... it falls out," McAvoy explained, though he quickly added, "maybe or maybe not."

McAvoy was then asked if he just gave out spoilers on something that he should have kept a secret, and the actor answered yes.

"I just (expletive) myself because I know, Fox Studios who own me might be angry with me for sharing that," he laughingly said.

In the comic books, Professor X loses his hair at an early age because it was the negative side effect of his mutant powers. In the movies, on the other hand, Professor X is already 40 years old and his hair loss might have something to do with the battle he and his fellow mutants will have against Apocalypse, who is deemed as the "first and most powerful mutant."

Incidentally, McAvoy's co-star in the film "Victor Frankenstein" Daniel Radcliffe is also sporting a bald look, and the two really stood out while they were out promoting the film inspired by the work of Mary Shelley.

During an interview with Jimmy Fallon in "The Tonight Show," Radcliffe is considering whether or not he would maintain his shaved head, since he is actually worried about the awkward growth stage.

"I'm reliably told by everybody who has done this that there is a stage of re-growth in between getting back to normal hair, where you kind of just look like a toothbrush, to use my friend's words," he said. "I feel like I'm on a press tour at the moment and I don't really want to treat you all to that, so I just kept shaving it."

Radcliffe added that he felt great that he looks fine with a shaved head.

"I was quite relieved because I shaved it on camera for the film and I've never shaved my head before so I was like, 'I don't know what's under there.' It might be a lump or a birthmark, I don't know. It all turned out fine, which I was relieved by."

"X-Men: Apocalypse" will be released on May 27, 2016.