Deadpool is chock-full of recommendations to other Marvel films. In fact, it’s so self-aware that at one point, Deadpool belts a picture of Hugh Jackman over his face. (So meta!) Not only does the silent picture refer to the X-Men several times, but it introduces one new mutant to the cinematic cosmos and brings back another: Negasonic Teenage Warhead (Brianna Hildebrand) and Colossus (said by Stefan Kapicic). They’re not exactly Deadpool’s sidekicks, but they are driving for him to join their team of superheroes. Here’s what you need to conscious about their characters in the comic books, and read carefully, because there’s a big conceivability they’ll appear in the already-in-development Deadpool sequel.