As it's a Fox movie, "Deadpool" was free to use all the Marvel characters that the movie studio owns the film rights to -- and that includes the X-Men. The massive blockbuster brought veteran X-Man Colossus to the big screen in a big way, and -- as screenwriters Paul Wernick and Rhett Reese revealed during their appearance on The Q&A Podcast -- introduced a new version of Negasonic Teenage Warhead.
Negasonic is a minor character from the X-Men comics, appearing in one issue of Grant Morrison's "New X-Men" and as an imaginary villain in a later "Astonishing X-Men" arc written by Joss Whedon, and the screenwriters revealed that they chose her solely because of her name. When it came to her powers, though, the writers wanted to do something different than the precognitive/telepathic abilities she had in the source material. Rhett Reese said they wanted to change her "into a literal warhead because we thought it was funnier." That, as they learned, was easier said than done.
"It was the one thing we needed Marvel’s actual approval on, that they had to reach out for," said co-writer Paul Wernick. "[Director] Tim [Miller] has a relationship with [Marvel President] Kevin Feige and I think he went straight to Kevin because all the lawyers, you know, it gets messy with the lawyers." Marvel obviously gave their blessing because the character, played by Brianna Hildebrand, uses her explosive powers throughout the film without a trace of her comic counterparts precog powers.
"Deadpool" is in theaters now.