The Marvel Cinematic Universe is more successful than ever before. It is wrapping up a decade's worth of storytelling, and with Disney possibly on the verge of acquiring Fox, it looks like there will be another decade of new characters and stories being introduced. Marvel managed to figure out the magic formula that keeps eluding Warner Bros. and their DCEU: the MCU produces movies that are hits with hardcore comics fans, but they also have very solid mainstream appeal. And a large part of that appeal comes from the fact that these actors are just so damn pretty!

Whether you're admiring the way Black Widow fills out her leather catsuit or simply wondering how Thor's biceps could be that big without exploding, there's a lot of eye candy going on in the MCU. That's what makes it so jarring when you discover these embarrassing pictures of these sexy and confident stars. Sometimes, your favorite actors are posing for mugshots. Other times, they're busy taking the worst yearbook photos ever. And occasionally, they'll have lost so much weight for a role that you barely recognize them. Want to see just how weird these photos get? Keep scrolling to check out 15 pics of MCU stars we weren't supposed to see!

15 ROBERT DOWNEY, JR.

In many ways, Robert Downey, Jr. represents the heart of the Marvel Cinematic Universe. His hero, Iron Man, launched the MCU back in 2008, and he's helped keep the universe together with cameos in movies such as Captain America: Civil War and Spider-Man: Homecoming. However, these photos are enough to make you forget about all of that star power!

If you didn't know, Downey was quite the bad boy when he was younger. How bad are we talking? He was arrested on multiple occasions, and in addition to the sad sight of a young actor nearly throwing his life away, he gave some pretty terrible mugshots. Fortunately, Downey's success in the MCU represents a kind of personal redemption as well, and it shows just how far his life has come from being that young man behind bars.

14 TOM HIDDLESTON

Tom Hiddleston as Loki is often held up as the exception to the MCU's villain problem. That is, most MCU villains tend to be one-note characters with little to no motivation. Hiddleston, however, had both the charm and the dramatic chops to be the primary villain in the first Avengers movie. Part of that charm comes from being so damn sexy...but you can't really tell in this picture!

There's a lot to take in here, and it ranges from his weird shabby chic clothing ensemble to that wacky mop of red hair on the top of his head. If you were told that Hiddleston would one day be a villain in superhero movies, you'd probably assume “young Lex Luthor” based on this picture. Fortunately, Hiddleston grew out of this awkward phase, and the actor now hardly needs Loki's magic staff to make people want to obey him!

13 CHRIS PRATT

Chris Pratt ended up being a secret weapon for the MCU. Many fans had no idea what to expect from the actor -- if they knew him at all, it was from his hilarious role as Andy Dwyer on Parks and Recreation. In Guardians of the Galaxy, Pratt gave us a perfect blend of sexiness and silliness...but there's not a lot of that going on in this picture!

This image was taken way back in 2002, which was a time when many of Star-Lord's biggest fans were mere toddlers (or maybe just a twinkle in their dad's eye). The future hero was attending the Teen People American Music Awards, and he might as well as have in a secret identity, as Pratt looks completely out of place in glasses. If he needs eyewear, we'd much prefer he puts on his iconic Star-Lord mask!

12 CHRIS HEMSWORTH

In some ways, this image is one of the most shocking on this list. As Thor, Chris Hemsworth has built a reputation as being the really buff Avenger...and when you're regularly standing next to Chris Evans, you can see why Hemsworth's biceps always go the extra mile! In this photo, though, he looks like he's on death's door.

What's going on here? Just Hemsworth really throwing himself into a part: he was on a journey to lose weight to play a shipwrecked survivor in the movie Lost at Sea. The giant muscles of Thor would have been completely out of place, so Hemsworth ate only five hundred calories a day so he would look the part. Though no one needs to worry -- as Thor: Ragnarok showed us, Hemsworth is still bringing his body's “A game” to the MCU!

11 CHRIS EVANS

Chris Evans seems destined to play comic characters on the big screen. We've seen him as the Human Torch in two Fantastic Four movies, and we've seen him as Lucas Lee, one of the “evil exes” of Ramona Flowers in Scott Pilgrim. Once he became Captain America, the world fell in love with his portrayal of this iconic character. This photo helps remind Evans of his humble origins, though.

And it doesn't get more humble than this. Before he was ever an onscreen hero, Evans modeled as “Tyler,” one of the potential suitors in the board game Mystery Date. Is it a pretty embarrassing game to be associated with? Maybe, but Evans gets the last laugh: all these years later, and more people want to go on a date with him (mysterious or otherwise) than ever before!

10 JEREMY RENNER

While he doesn't always get the respect he deserves, Hawkeye plays a vital role as the everyman figure of the Avengers. And it helps Jeremy Renner's appeal that he is so effortlessly cool, and it's easy to see why he was once the frontrunner to take over the Mission: Impossible franchise. However, you'd never guess that based on this photo!

Way before he was a super spy or a superhero, Jeremy Renner starred in National Lampoon's Senior Trip. In the movie, Renner plays a teenage prankster whose antics end up getting him roped into a scheme to embarrass the president. As it turns out, this movie is the real embarrassment, clocking in at a whopping zero percent on Rotten Tomatoes! Chances are Renner doesn't want anyone to remember this movie, but maybe Hawkeye can bring back this haircut?

9 SCARLETT JOHANSSON

As Black Widow, Scarlett Johansson ended up perfectly embodying the ideals of comic book greatness. She's got style, swagger, and spy skills, and she wraps it all up in a tight leather outfit. However, this photo helps to prove that even the most outstanding people had their own awkward teenage years.

The image is from a premiere party for the debut of the film The Horse Whisperer, which was an early role for the actress. While no one can say she looks ugly in this photo, things do look a bit awkward: forced smile, wary eyes, and the stance of someone ready to kill the next person that snaps her picture. She was only 14 in this photo, and eventually managed to do what most of us only wish we could do: grow more in both beauty and poise. Both beautiful and deadly: the perfect combination for Black Widow!

8 ROBERT DOWNEY, JR.

For Robert Downey, Jr., not every embarrassing photo is a mugshot (although he has several of those). In this case, the picture is the kind of embarrassing that all of us can appreciate when we stumble on an old photo. This is a picture that reminds all of us of our own mortality.

Downey is only 20 years old in this picture, and he has both his personal and professional life ahead of him. No one can deny that Downey has had a hell of a ride on both fronts, but the veteran actor is now over fifty years old. Seeing this image is a reminder that entire decades can fly by faster than any special suit of armor ever could. But hey, at least comic book movies help us feel young again!

7 MARK RUFFALO

Mark Ruffalo entered the MCU with the unenviable job of filling some else's shoes. Previously, Ed Norton had played the role of Bruce Banner in our one (and likely to be only) solo Hulk movie. Fortunately, Ruffalo nailed the role with a perfect nervous charisma that helped to endear us to the character and give us a great contrast with Hulk himself.

This photo, though, is anything but nervous. What's going on here? This was actually from a photoshoot Ruffalo did for W. Magazine. While Ruffalo is a good-looking man and rocks the hell out of his bare chest, the costume is way too extra, making it look like he shredded some of Doctor Strange's clothing so he could dress like a bird in his spare time!

6 TOM HOLLAND

So far, Tom Holland represents our youngest addition to the main MCU characters. As both Peter Parker and Spider-Man, he does a great job at bringing Marvel's most iconic character to life. Holland became a worldwide star overnight after Captain America: Civil War premiered, but these photos highlight the actor's very humble start.

These images represent Holland when he was auditioning and then performing in his very first professional role. It wasn't on the big screen, though, but onstage in a performance of Billy Elliot. Holland's casting was a miracle, as his actual audition was terribly awkward. The show's director saw the star power underneath, but it's still fun to check out these awkward moments in the history of the man who would be Spider-Man!

5 SCARLETT JOHANNSON

Most of the pictures on this list are embarrassing because they are reminders of the actor's awkward years. These are the times when stars were a little chunkier or simply rocking some wild hair (we're looking at you, Jeremy Renner). Every now and then, though, it's not the MCU star that's being awkward. Sometimes it's John Travolta!

This particular picture comes from the 2015 Oscars. As you know, this is a time and place when many stars act in a silly and unpredictable manner. And Travolta was certainly being unpredictable when he suddenly leaned in and gave Scarlett Johansson a kiss. Pretty much everyone looking thought it was the most awkward thing ever, and while ScarJo would later describe it as “totally welcome,” she certainly looks ready to murder Travolta in this picture.

4 JEREMY RENNER

When it comes to Jeremy Renner, you may have thought it couldn't get more awkward than the wild hair he was sporting for the Senior Trip movie. However, we all know that Hawkeye never misses. And in this case, he's been right on the mark when it comes to terrible hair for decades.

These photos reveal some of Renner's more awkward yearbook photos. This is the kind of blast from the past that we can only imagine the real Hawhkeye would have had S.H.I.E.L.D. wipe all evidence of it away. While it's true that nobody takes really good yearbook photos, very few of us have an honest-to-god power mullet in our history. And for that, we salute you, Renner: business in the front, Marvel in the back!

3 TOM HIDDLESTON

There's no other way around it: Tom Hiddleston is one of the sexiest guys on the planet. Even though he plays one of the most iconic and devious villains in the MCU, audiences find themselves agreeing with much of what this handsome trickster says. However, we might think twice about listening to the guy in this photo!

Most of the embarrassment comes down to the unfortunate hair. Close and curly, Hiddleston's hair manages to accentuate his ears, making him look a bit like the Mad Magazine mascot Alfred E. Newman. The future sex icon is also pictured in the middle of making a face, and it all adds together to make him look like one of the more handsome leads in a Revenge of the Nerds movie.

2 MARK RUFFALO

Mark Ruffalo plays both Bruce Banner and The Hulk in the MCU. One of the things that he captures really well is Banner's constant fear of “the other guy.” The super-scientist may be a bit shy and nerdy, but he always knows that if he loses control, his skin will turn all green. In these pictures, though, Ruffalo was worried about entirely different skin issues!

These pictures come from a time well before he was Mark Ruffalo, movie star. Here, we see him as the star of a Clearasil commercial. Ruffalo plays an impossibly fresh-faced young man who is worried about keeping his skin looking as clear as possible. While it's easy for us to laugh at young Ruffalo, the joke's on us: he eventually took his clear and pretty face all the way to the bank!

1 CHRIS PRATT

Before Guardians of the Galaxy, many fans knew that Chris Pratt was a funny guy. Therefore, it wasn't that surprising that he was able to make Star-Lord such a genuinely charming and hilarious guy. However, Star-Lord surprised us all once he took his shirt off, showing an impossible ripped body. In these old photos, though, you might want Pratt to put the shirt back on!

In these photos from 2008, Chris Pratt is hanging at the beach with his wife, Anna Faris. To be fair, Pratt is deliberately being goofy and poking his belly out as he laughs with his wife, but it's tough to not notice that there's a whole lot more Pratt here than when he joins the MCU. Maybe all of us should make a New Year's resolution to get cast in a Marvel movie?