When it comes to comic book movies, a surefire way to bring out one's inner geek is to include superhero cameos. There's a particular kind of thrill that comes from seeing one's favorite characters join forces against an existential threat, especially when it occurs after a formulaic build-up of solo films and backstories. Marvel is clearly aware of this — its movies are well known for their epic team battles, and the studio is working hard to bring more of them to the big screen, especially after having successfully secured a number of Fox properties like X-Men, Deadpool, and Fantastic Four​​​​​​.