One of the most entertaining things about re-watching movies from the Marvel Cinematic Universe is looking for cameos. Whether it is characters from the comics books or past films that the directors throw in as a wink to hardcore fans or even stunt casting as smaller characters in scenes, Marvel seems intent on really working hard to give fans something to make their movies worthwhile. These cameos have happened ever since the earliest MCU movies, both with the hidden comic characters and the special guest stars.

RELATED: 16 DC Movie Cameos You Totally Missed

When watching the Incredible Hulk movies, it is easy to see cameos from actors like Lou Ferrigno, who played the Hulk on the classic TV series. It is even easier to spot the Stan Lee cameos that have taken place in every movie in the Marvel Universe. All comic book fans know that Jarvis was the butler in The Avengers and that Iron Man’s AI is a homage to that. However, there are also smaller cameos that fans might miss out on, or ones only hardcore fans will catch. With 16 MCU movies out and Thor: Ragnarok making 17, here is a look at the best MCU cameos from the movies you totally missed.

15 CAST MEMBERS OF COMMUNITY

MCU Cameos You Totally Missed

The Russo Brothers have become vital members of the Marvel Cinematic Universe family. Anthony and Joe Russo directed Captain America: Winter SoldierCaptain America: Civil War, and both Avengers: Infinity War and its sequel. Before they joined the MCU, the Russo Brothers were not known for action directors but instead as comedy masterminds. They worked on both Arrested Development and Community.

Fans of Community are getting a lot of chances to see their favorite actors show up in the MCU. Danny Pudi played a communications tech in Winter Soldier and Jim Rash played an MIT liaison in Civil War. Donald Glover was in Spider-Man: Homecoming as the criminal that Spider-Man questions in the parking garage. All we need now is for that photoshop of Alison Brie as Captain America to come true, and we'll have an almost full set!

14 PETER PARKER

MCU Cameos You Totally Missed

There could be arguments whether the Peter Parker cameo in Iron Man 2 was done on purpose at the time or not. For example, there were a lot of rumors that the kid that helped Tony Stark in Iron Man 3 might grow up to be Star-Lord but that turned out to be false. However, actor Tom Holland (Spider-Man: Homecoming) has said that this one cameo and rumor turned out to be true, and why would he have a reason to lie?

What happened here was that around the end of Iron Man 2, one of Justin Hammer's drones was on the rampage and came face-to-face with a child wearing an Iron Man mask as part of his costume. The kid raises his hand at the drone, and as it is ready to kill the child, Iron Man sweeps down, blasts the drone, and says "nice work kid" before flying off. Holland said that the rumors were true and that child was Peter Parker.

13 ELON MUSK

MCU Cameos You Totally Missed

In Iron Man 2, Tony Stark is at an extravagant party at a race car track, mixing and mingling with other wealthy and influential people. In Marvel Comics, Tony is one of the smartest men alive and an innovator that has brought some of the world's greatest inventions to life. It should come as no surprise that Stark would meet like-minded people at a party such as this. He did that when he ran into Elon Musk.

Of course, Elon Musk is a real-life innovator and one of the smartest people alive. He has helped found a company offering space travel, is developing an underground Hyperloop train system and made his fortune with PayPal and Telsa motors. If there is a real-life version of Tony Stark, it is Elon Musk, and it is cool that he appeared in Iron Man 2 as a contemporary of Stark.

12 MICHAEL ROSENBAUM

MCU Cameos You Totally Missed

James Gunn has no problem with casting his friends in roles in his movies, especially in parts where no one will ever see their face. He cast Nathan Fillion under monster prosthetics. He cast Rob Zombie to simply voice the AI of a spacecraft. Gunn also cast Lex Luthor himself to play a role in Guardians of the Galaxy 2.

Michael Rosenbaum played Lex Luthor in Smallville on The CW. After that show went off the air, Rosenbaum took on some smaller roles and even appeared in some short films that Gunn shot in between his larger movie projects. When it came time for Gunn to make his Guardians sequel, he called on Rosenbaum and cast him as one of The Ravagers, alongside Sylvester Stallone. Rosenbaum was unrecognizable as Martinex, the crystal covered Ravager.

11 ANDROID HUMAN TORCH

MCU Cameos You Totally Missed

Captain America: The First Avenger was the first and so far only historical movie in the Marvel Cinematic Universe (at least until Captain Marvel). Since it took place during World War II, there were a lot of chances to have cameos from that era of Marvel's history. Of course, the most significant appearances was the Howling Commandos, especially Dum Dum Dugan. They returned for Agent Carter on TV, but there was another group from World War II-era Captain America comics that the film referenced.

The Invaders was a team that Captain America was a member of at the time that consisted of Cap, Bucky, Namor, the android Human Torch Jim Hammond and his sidekick Toro. At the Stark Expo, there are many things on display, and one of them is the android Human Torch in an oxygen-deprived container. It was a fun reference to one of the first ever superhero teams in the Marvel Comics universe. It is also funny because before he was Captain America, Chris Evans played The Fantastic Four version of The Human Torch.

10 UNION JACK

MCU Cameos You Totally Missed

In the World War II-era Marvel Universe, Captain America was a member of The Invaders. During that comic book's run, the team encountered a man named Brian Falsworth, whose father was a hero known as Union Jack during World War I. In The Invaders comics, Thomas became the superhero Union Jack and joined The Invaders for a time. He went on to become one of Britain's top heroes thanks to the influence of working alongside Captain America.

In Captain America: The First Avenger, James Falsworth (Thomas' father's name) was a member of The Howling Commandos. HYDRA captured him during the movie and Captain America came along and saved him when he raided the base, freeing all the imprisoned soldiers and trying to stop the Red Skull. In The Avengers, some files Cap views show that Falsworth died, so he was just there as a fun cameo for fans but never became Union Jack in the MCU world.

9 WALT SIMONSON AND J. MICHAEL STRACZYNSKI

MCU Cameos You Totally Missed

The first Thor movie took the chance to honor two of the comic book character's most successful creators. The first cameo was that of Walt Simonson. Simonson wrote the acclaimed run of Thor in the mid-'80s and is the man known as the creator of Beta Ray Bill. He appeared in a small cameo on Asgard at dinner beside Sif. On a side note, some shots from Thor: Ragnarok were lifted straight from Simonson's Thor run.

The second cameo from Thor took place on Earth when Mjolnir was planted solidly on the ground in New Mexico. A truck driver showed up to try to pull it off the ground, unsuccessfully, before S.H.I.E.I.D. showed up and set up shop around it. The truck driver who unsuccessfully tried to lift Mjolnir was J. Michael Straczynski. He is the writer responsible for moving Asgard to Oklahoma in the comic books, an influence on the New Mexico scenes in Thor.

8 NATHAN FILLION

MCU Cameos You Totally Missed

When James Gunn directs a movie, there is a good chance he calls on some close friends. The first film that Gunn directed after leaving Troma Studios and moving on to Hollywood was a great little horror movie called Slither. That film featured alien slugs that infected people and turned them into slug-like monsters. The hero of Slither was a police chief played by Nathan Fillion.

James Gunn and Nathan Fillion became friends, and the two collaborated on some smaller short projects over the years. When it came time for Gunn to make Guardians of the Galaxy, he called Fillion. While Fillion was rumored to possibly appear as Wonder Man in the MCU, that didn't happen. Instead, Fillion guest starred as the voice of the alien above, who was incarcerated at the prison from which the Guardians escaped.

7 LLOYD KAUFMAN

MCU Cameos You Totally Missed

James Gunn got his start working for the legendary and ultra-successful Troma Studios. The most prominent independent film company of all-time remains known for films like The Toxic Avengers and Sgt. Kabukiman N.Y.P.D., but Gunn worked on what many critics consider the best film in the history of the company, Tromeo and Juliet.

Gunn wrote Tromeo and Juliet, and that was enough to launch a career that moved on to Hollywood and soon to the Marvel Cinematic Universe. Gunn has always credited Troma head-honcho Lloyd Kaufman as the reason he was able to get his start in the film business and gave Kaufman his own Stan Lee-styled cameo in Guardians of the Galaxy. Kaufman was one of the prisoners who was taunting Gamora when the Guardians entered the space prison.

6 ELLEN BRANDT

Ellen Brandt in Iron Man 3

In Iron Man 3, Tony Stark ended up in a small town in Tennessee when his armor saved his life after the Mandarin attack on his home. While in this small town, Stark met a young boy and tried to start working on some new weapons to try to head out to take the fight to the Mandarin. However, before he could leave the town, a few of the Extremis soldiers showed up and started wrecking havoc. One of these soldiers is Ellen Brandt, a woman who lost her arm and received the Extremis virus to become a weapon for A.I.M.

However, in the comics, Ellen Page is a character from the pages of Man-Thing. In the comics, Ellen married Ted Sallis but then betrayed him by joining A.I.M. and plotting against him to steal his work. Ted tried to inject himself with a super soldier serum and ended up driving into a swamp and becoming Man-Thing. Ellen freaked out and burned half her face in the aftermath. In Iron Man 3, this version of Ellen Brandt also has scars on half of her face.

5 DR. YINSEN

MCU Cameos You Totally Missed

Think back to the very first movie in the Marvel Cinematic Universe, Iron Man. Tony Stark was injured in an explosion and then kidnapped by the Ten Rings, held in a cave, and ordered to make weapons for the terrorists. While in the cave, he meets another prisoner named Dr. Yinsen, who tells Stark that they had met before. However, Yinsen remembers that Stark was drunk and likely doesn't remember it, although he still gave a fantastic presentation at the time. Yinsen then helps Stark escape by sacrificing his own life.

In Iron Man 3, director Shane Black took a chance to give some payoff that storyline. In that movie, the bad guy Aldrich Killian is explaining how Stark dismissed him at a party many years before and drove him to create A.I.M. and seek revenge. That was the same party that Dr. Yinsen was at, and the movie shows the exact scene described in the first Iron Man movie for fans paying attention.

4 ED BRUBAKER

MCU Cameos You Totally Missed

There was a creator cameo that took place in Captain America: Civil War, and it might be one of the most deserving cameos in all of the Marvel Cinematic Universe. Remember that in Civil War, it turns out that Bucky Barnes did not die in World War II and was instead captured and turned into an assassin, tortured and implemented with a code word that triggered his missions. The movie showed how HYDRA accomplished this.

In the comics, it was close to the same story as Bucky was captured and turned into an assassin through mind-control. The writer of the Captain America comics when Marvel resurrected Bucky and introduced Winter Soldier was Ed Brubaker. In the Winter Soldier movie, it was Brubaker that worked to program Bucky into Winter Soldier, much like his writing developed Winter Soldier into a character in the comics.

3 DR. HELEN CHO (AND AMADEUS)

MCU Cameos You Totally Missed

In Avengers: Age of Ultron, Ultron is trying to set his plan in motion, and he forces a doctor associate of S.H.I.E.L.D. and The Avengers to help him use synthetic-tissue tech to help sculpt a new body for him out of vibranium and an Infinity Gem. This doctor is named Helen Cho, and she happens to be the mother of Amadeus Cho in Marvel Comics.

For those who might not recognize the name, Amadeus Cho is the eighth-smartest person in the entire Marvel Universe and was, for much of his comics life, a sidekick to Hercules and the Hulk. As a matter of fact, Cho became The Totally Awesome Hulk in 2015. Speaking of Amadeus, there is a good chance he had a cameo long before his mother did. In The Incredible Hulk, there was a student who Bruce Banner bribed with pizza to let him into a science lab. The novelization of the movie said that student's name was Amadeus Cho.

2 JACK MCGEE

MCU Cameos You Totally Missed

In a small cameo that no one could have expected to catch when watching The Incredible Hulk in the movie theater, there was a reference to the classic TV show starring Bill Bixby and Lou Ferrigno. This cameo was not the appearance of Ferrigno as the security guard but was instead just a couple of guys who were trying to film the rampage of The Hulk when Thunderbolt Ross began the battle with him in on the college campus. The two characters were named Jim Wilson and Jack McGee.

Jim Wilson, in the comics, is the nephew of The Falcon and a sidekick for the Hulk for a short time. However, Jack McGee was a huge name -- the investigative reporter who was searching for proof that The Hulk existed in the Incredible Hulk television series. Since Jack McGee was shooting video of the battle, it is a possibility that he could grow up to become the same Jack McGee who searched his whole life for The Hulk.

1 THE LEADER

MCU Cameos You Totally Missed

There were two cameos in The Incredible Hulk that had to do with superhumans in his comic book canon. The first was the boyfriend of Betty Ross. This man was Leonard Samson, played by Modern Family actor Ty Burrell. He is a psychotherapist in the movie, but in the comics, he is Doc Samson, a psychotherapist exposed to Gamma radiation that develops green hair and super strength.

A more exciting cameo, though, was Samuel Sterns, the man who was trying to help Bruce Banner find a cure for his problems. In the comics, Sterns is The Leader, a highly intelligent supervillain exposed to Gamma radiation and one of Hulk's most deadly enemies. In The Incredible Hulk, he gets Gamma radiation leaked on his forehead towards the end and looks like he is turning into The Leader from the comics.

Which other hidden cameos did you catch in the MCU so far? Let us know in the comments!