Bryan Singer's X-Men: Days of Future Past aims to unite mutants from two different timelines on screen, but one familiar face who won't be featured is that of comics legend Stan Lee.  Known for making brief cameos in Marvel films (that are arguably either a fun bit of fan service or awkwardly distracting), Lee has appeared in 17 superhero movies in the last 13 years.  Though 2000's X-Men was his first appearance, that particular franchise has proven the most inconsistent, as he only had cameos in the original film and X-Men: The Last Stand.  While his trend of absences in X-Men films will continue with X-Men: Days of Future Past, this isn't the end of his cameo days; fans can look forward to seeing Lee in future Marvel movies for sure.  Hit the jump for more.

Bleeding Cool reports that Lee informed the audience at Toronto's Fan Expo that he could have filmed a cameo for Singer's new film in Montreal this weekend, but chose to visit the convention instead.  Lee's age - he'll turn 91 this December - may have been a factor in his absence from James Mangold's The Wolverine, as the Australia/Japan shooting locations were a bit too far for him to travel.

In addition to the two X-Men films he made appearances in, Lee popped up in various disguises in all three Sam Raimi Spider-Man movies, plus Marc Webb's The Amazing Spider-Man, Daredevil, both Hulk and The Incredible Hulk, the two Fantastic Four movies, all three Iron Man movies, Thor, Captain America: The First Avenger and last year's The Avengers.  Lee is expected to appear in Webb's follow-up, The Amazing Spider-Man 2, especially since he tossed in some of his own ideas for the part.  It's also pretty clear that he'll be showing up in Thor: The Dark World and Captain America: The Winter Soldier, which directors Joe and Anthony Russo talked about here.  It's safe to say that we can expect Lee to continue his cameos as long as Marvel is making movies; here's hoping for a long run for both of them!

You can watch all of Lee's cameos up to and including Iron Man 3 below: