All the real-life clues that pointed to that jaw-dropping 'Eternals' end-credits cameo

• Warning: There are major spoilers ahead for Marvel's "Eternals."
• The film features two end-credits scenes, one of which marks the debut of Harry Styles as Eros.

Marvel's latest film as part of phase four, "Eternals," confirms a longstanding rumored celebrity appearance in the second end-credits scene.

In typical Marvel fashion, the film concludes with two scenes that tease major ramifications for the MCU.

The first scene introduces Harry Styles as Eros, who comic-book fans will recognize as the brother of the Mad Titan named Thanos (played by Josh Brolin in the Infinity Saga).

In the scene, Eros (also known as Starfox in the comics) and Pip the Troll (voiced by Patton Oswalt) meet the Eternals Thena (Angelina Jolie), Makkari (Lauren Ridloff), and Druig (Barry Keoghan) on their spaceship. After flirting with Thena, Eros holds a glowing sphere (similar to the one used by Ajak and Sersi to communicate with the Celestials) in his hand and delivers an ominous message: "Your friends are in big trouble. And we know where to find them."

Coincidentally, Styles and Keoghan previously worked together in Christopher Nolan's 2017 war film "Dunkirk."

The second scene teases Kit Harington's character, Dane Whitman, becoming the comic-book superhero Black Knight.

Styles' appearance in the MCU, and "Eternals" specifically, was first speculated about in 2019 and was spoiled after the film's Los Angeles premiere on October 18.

In an interview with Insider's Kirsten Acuna, Ridloff revealed that Styles' end-credits scene was filmed in January 2021 during reshoots.

Here are all the real-life clues that pointed at the Grammy-winning singer's involvement in "Eternals."

May 28, 2019: Styles attended Gucci's Cruise 2020 fashion show and posed for a photo with 'Eternals' star Salma Hayek and fellow Marvel actress Zoe Saldana

The photo of Styles with Saldana and Hayek was reposted by a fan account on Twitter.

Styles' appearance was expected, given his friendship with Gucci's Alessandro Michele, who he met in London in 2014. The "Kiwi" singer has often worn Gucci outfits on tour, red carpets, and magazine covers.

Saldana has worn Gucci at events and previously appeared in a short film for the brand.

Hayek has maintained a close relationship with Gucci as well, thanks to her husband Francois-Henri Pinault, who's the chairman and CEO of the luxury-goods brand Kering. The company's portfolio includes Gucci and other fashion houses.

Hayek has dressed in Gucci outfits on red carpets over the years and will star in the upcoming film "House of Gucci."

September 9, 2019: Fans noticed that 'Eternals' star Richard Madden started following Styles on Instagram

Madden, who portrays the Eternal named Ikaris, follows less than 400 people on Instagram. This includes stars like Styles, Tom Hiddleston, Tom Holland, and John Krasinski.

That same month, the cast of Eternals was in London filming the movie. Styles was also seen in London taking photos with fans.

This coincidence, plus the timing of Madden following Styles on Instagram, led people to speculate that Styles could be in "Eternals," though the evidence was still thin at that point.

December 5, 2019: Styles followed Madden back on Instagram

Styles follows less than 400 people on his Instagram, including "Captain Marvel" star Brie Larson, his "Don't Worry Darling" costar Florence Pugh, and his rumored girlfriend Olivia Wilde, who directed and also appears in "Don't Worry Darling."

February 4, 2020: 'Eternals' star Gemma Chan revealed that filming wrapped

The actress, who plays Sersi, posted a black-and-white mirror selfie in which she was seen wearing a cap with the 'Eternals' logo on it.

September 11, 2020: Netflix writer Kris Tapley tweeted and deleted a post in which he said Styles would appear in a Marvel movie that 'no one knows he's in'

In the since-deleted tweet, Tapley quoted a tweet from Deadline reporter Justin Kroll about Styles landing his first acting role since "Dunkirk" in Wilde's "Don't Worry Darling."

The tweet read, "EXCLU: In his first acting gig since DUNKIRK, Harry Styles is set to join the ensemble of @oliviawilde next directing job DON'T WORRY DARLING."

In response, Tapley said: "Second if we're counting the Marvel movie no one knows he's in."

Although he removed the tweet, fans were quick to take screenshots of the post beforehand.

September 16, 2020: Graphic artist BossLogic shared artwork of how Styles would look as the Marvel character Starfox

People suspected that Styles would be playing Starfox in "Eternals" given the character's connection to the Eternals in the comics, coupled with the singer's aforementioned interactions with the cast in person and on social media.

January 2021: According to Madden, filming wrapped in January 2021 but reshoots and other production aspects were ongoing

The actor spoke about reshoots in an interview with British GQ. This actually turned out to be the month that Styles filmed his end-credit cameo, Ridloff later revealed.

February 1, 2021: Hayek wished Styles a happy birthday on Instagram

Hayek posted the photo of her and the actor at the Gucci Cruise fashion show on her Instagram story with the caption: "Happy birthday @harrystyles."

Fans thought the post was unusual, with one person tweeting: "why would salma hayek wish harry happy birthday if they only met once....unless it wasn't just one time and they worked on a movie together........"

February 17, 2021: 'Eternals' director Chloé Zhao wore a shirt from Styles' merch collection in her Time 100 Next photo shoot

Zhao posed in a white T-shirt with Styles' signature phrase, "Treat People With Kindness," printed in rainbow lettering.

The director could have been wearing the apparel because she's simply a fan of the "Watermelon Sugar" singer, but fans of Styles know that he often gives free merch and other gifts to cast and crew members that he works with.

March 30, 2021: A leaked, detailed description of 'Eternals' circulated on Reddit, claiming that Starfox would appear in the film's second end-credit scene

The leak came from an individual who claimed to have been present at an early test screening of "Eternals."

The information about the end-credits scenes read:

"The two end credit stingers: 1) Dane is looking at an old box and pulls out a sword that is wrapped up. Just as he is about to touch it, an off screen voice stops him. 2) On the Eternals' ship, Pip the Troll appears and introduces Starfox."

Now that the movie has officially been released, fans know that these descriptions turned out to be accurate. However, the order of the scenes was switched.

June 15, 2021: Hayek appeared virtually on 'The Ellen DeGeneres Show' and recalled her pet owl, Kering, coughing up a hairball on Styles' head

"He was really excited about the owl and was hoping the owl would go on his head, because it was on me," Hayek recalled, not naming the celebrity at first. "He was like, 'Oh, I need an owl in my life. How do you do that?"

"The minute he least expected it, it came on his head but then this ball of rat hair was on his head."

Before wrapping her interview, DeGeneres asked Hayek to name-drop the celebrity and that's when she mentioned Styles.

"I hope I'm not in trouble," Hayek said. "He was super cool, by the way. He was super cool even with that happening."

August 13, 2021: Harington tried to dismiss rumors of Styles' involvement during an appearance on 'The Tonight Show Starring Jimmy Fallon'

When asked about the rumor, the actor shrugged his shoulders and said, "No idea, unless I've been recast and he's playing my part. I have not a clue."

Harington also said that he didn't run into Styles.

"I hear he's a great guy," he continued.

"Lovely chap, I think. I don't know, never met the guy," Harington said before laughing.