X-Men: Days of Future Past opened this past Memorial Day weekend to enormous box office success. And suave fans have noticed that the film is filled with easy-to-miss references to earlier films and subplots only found on the pages of the Marvel comic books. There are plenty of hidden Easter eggs to be discovered in this latest X-Men franchise adventure. Check out some of the moments you may have not noticed the first time around, before seeing X-Men: Days of Future Past again in theaters this week.

[1] The Maximoff Family

True X-Men fans know that Magneto (Michael Fassbender) is the real father of mutant siblings Quicksilver (Evan Peters) and Scarlet Witch. This is never said outright in the movie, but it is alluded to. When Quicksilver hears Magneto say that he can control metal with his mind, he responds by revealing that his mother knew someone that could do the same thing. The Maximoff name is also seen on the home mailbox of Quicksilver, confirming that, while it's never mentioned in the movie, Magneto and Quicksilver are, in fact, father and son. Maybe this will truly be revealed in X-Men: Apocalypse?

[2] What happened to some of the X-Men: First Class characters?

Before seeing the movie, some fans have wondered what happened to certain mutants between X-Men: First Class and X-Men: Days of Future Past, as we knew the actors weren't returning. In the latest movie, we actually learn that Angel, Banshee, Emma Frost, Riptide and Azazel have all perished during events seen off screen, leading into the X-Men: Days of Future Past storyline.

[3] Cameos

Chris Claremont, who wrote the original X-Men: Days of Future Past comic book storyline, is featured as a U.S. Senator alongside Len Wein, the man responsible for creating characters Storm, Colossus, Nightcrawler and the big daddy of all mutants Wolverine. Director Bryan Singer also works his way into the movie, and can be seen when Mystique bursts from the Paris hotel into the public square. He is a photographer capturing this historical first reveal of mutants to the general populace.

[4] Kitty Pryde and Colossus Are Finally Together

The end of the film reveals a timeline fix, which offers a happy ending for some of the mutants we've come to know so well. Two of those mutants are Kitty Pryde (Ellen Page) and Colossus, (Daniel Cudmore) who shared a long and loving relationship in the comic book, but never managed to come together on screen. Now that the timeline is fixed, these two young lovebirds are back in each others arms, as Marvel lore always intended.

[5] We're Living in the Future

In the original X-Men: Days of Future Past comic book, the future year is 2013, the exact same year the movie started production. Is this a coincidence? Perhaps not. In the film, the future year is now shifted to 2023.

[6] Time Traveling Kitty Pryde

In the original comic book, it was Kitty Pryde who went back in time to stop the Sentinels from destroying the mutant race. In the movie, Wolverine becomes the central character, but Kitty Pryde still gets a nod, as she is the one given time phasing powers that allow Logan to travel back to the 70s, where he meets The First Class.

[7] Star Trek and The Naked Time

Hank McCoy (Nicholas Hoult) is seen watching an old episode of Star Trek in his workshop. The episode is The Naked Time, which follows a similar story to X-Men: Days of Future Past. When James T. Kirk and the crew of the Starship Enterprise encounter a mind-altering infection, the crew is saved by an explosion that sends them back in time three days, where they are able to replot their course and avoid this horrible fate.

[8] Who Are the Enlisted Mutants?

Early in X-Men: Days of Future Past, Mystique (Jennifer Lawrence) rescues four enlisted mutants, who are being used by William Stryker as part of his experiments. But who are they? We get to meet a young Toad, who was introduced in the first X-Men. We also get to see Ink from the Young X-Men comic, Spyke from the X-Men: Evolution animated series, and Havok from X-Men: First Class.

[9] Future Sentinels Display Fallen Mutant Powers

Thanks to the capture of Rogue (Anna Paquin), the Future Sentinels are capable of absorbing any mutant's powers and sharing it amongst themselves to fight the few remaining survivors. While we see them use Sunspot and Iceman's powers against each other early in the film, we also get to see Future Sentinels using the powers of fallen mutants Lady Deathstrike, Emma Frost and Darwin.

[10] Wolverine Loves Yellow and Brown

While we still haven't seen Wolverine's iconic 80s yellow and brown costume on screen, his 70s apartment pays homage in an interesting way. Logan clearly loves the color combination, with yellow walls and brown and yellow curtains.

[11] Conflicting Timelines

The history between William Stryker and Wolverine in X-Men: Days of Future Past does not match up with the events seen in X2: X-Men United, which revealed that Stryker experimented on Wolverine, covering his bones in unbreakable adamantium. In X-Men Origins: Wolverine, the two meet for the first time in Vietnam. But in X-Men: Days of Future Past, Stryker is now 20 years younger and he has never met Wolverine before. This causes a rift in the franchise timeline, with overlapping and conflicting events.

[12] X-Men: First Class Props

In the scene where Magneto goes to steal his helmet back, we get to see some of the other props from the prequel, including the coin Magneto used to kill Sebastian Shaw, Havok's damaged harness, and one of Angel's dissected insect wings.

[13] X-Men Vs The Avengers

In a unique cross-sharing of characters, both Quicksilver and Scarlet Witch are owned by Marvel Studios and 20th Century Fox, which gives us the only crossover between Marvel's The Avengers and X-Men that we're likely to get for a very long time. Different actors play the characters in both franchises, which means its not a true crossover, and the mutants are reenvisioned as 'miracles' in the Marvel Cinematic Universe, since they are not allowed to reference mutants of any kind. Marvel is also not allowed to use Magneto, so X-Men: Apocalypse will be the only place father and son can work together as a team. But its rare, and pretty cool, that two completely different franchises can use the same characters and super powers to propel their stories forward.

[14] A Comic Page Homage

One of the classic images from the original comic book finds Magneto ripping metal out of Wolverine's body. We get a similar scene here, which finds Magneto impaling Logan with metal rods. While the idea is a complete 360, the image of this twisting metal jutting out of Logan's body is directly referenced in the pages of X-Men #25 from 1993.

[15] The Four Horseman

We know the hooded figure we see during the post-credits scene of X-Men: Days of Future Past is En Sbah Nur, otherwise known as Apocalypse. He will be the central villain in the next franchise sequel, X-Men: Apocalypse. But did you know the four men quickly glimpsed on horses are the Four Horsemen: War, Pestilence, Famine, and Death? They are clearly being teased for a bigger role in the next movie.