A key figure in developing several characters in the cosmic side of the Marvel Comics universe, writer and artist Jim Starlin’s works are quickly becoming a prominent part of the films as well. By the time The Avengers hit theaters in summer 2012, we had already seen a few of his creations at play – from the Infinity Gauntlet shown briefly in Thor, hidden away in Odin’s Vault on Asgard, to the grinning Thanos in the mid-credits button of The Avengers. ‘It’s all connected’ as the marketing slogan for Marvel’s Agents of S.H.I.E.L.D. would remind us.

Later this year, we’re going to meet at least several more of Starlin’s characters in Guardians of the Galaxy, a film that will finally offer a little background on big bad Thanos and give moviegoers a reason to be keeping him in mind for future films. Starlin had mentioned last year at Montreal Comic-Con that Thanos was going to be coming back in not only Guardians of the Galaxy but The Avengers sequel as well, adding credence to theories that after we meet Star-Lord, Drax the Destroyer, Gamora, Groot, and Rocket Raccooon this August, they may make their way to Earth to meet the heroes we’re already familiar with. Why else would the cosmic heroes and villains be introduced this year, right?

Click Image for Larger Version.

While the release schedule of the Phase 2 films may suggest something to that end occurring, we already know Joss Whedon’s The Avengers: Age of Ultron is dealing with another new villain named Ultron (and his robotic army) instead. We don’t know what new origin story Joss Whedon has come up with for Ultron (in the comics, Hank Pym aka Ant-Man created him), but for now we’re going to assume it’s Earth-based. Come time for The Avengers 3 however, and the Guardians of the Galaxy and the larger cosmos will definitely be involved.

So says GOTG writer and director James Gunn in an interview with EW.

“We’re definitely connected to Avengers 3.”

As for how? Look towards the Mad Titan we know as Thanos coming to Earth as the most likely reason. The character’s been kept behind-the-scenes out in space throughout the events on Asgard and Earth we’ve seen take place in the Marvel Cinematic Universe to date, but we will see him again in Guardians of the Galaxy.

Thanos Concept Art – The Avengers

Thanos Helmet – The Avengers

No voice actor has been cast yet to bring Thanos to life, or at least announced, but Gunn confirms that Thanos will be motion-captured and animated, just like Rocket Raccoon (voiced by Bradley Cooper) and Groot (Vin Diesel). Gunn describes Thanos’ role in the villain hierarchy as the the “head of the snake.” Expect Thanos to play a key role in Guardians of the Galaxy despite having what we expect to be minimal screentime as his henchman Ronan the Accuser (Lee Pace) steps up as the primary antagonist of the film.

Warning: Don’t read on if you’ve not seen Thor: The Dark World

Ronan, alongside Gamora (Zoe Saldana) and Nebula (Karen Gillan), all share history with Thanos, as revealed in the official Guardians of the Galaxy prequel comic. Ronan was a mentor of sorts to the pair of lethal ladies, who are seemingly bio-engineered super assassins. For some reason, Thanos punishes them harshly (we won’t spoil how) and it caused Gamora to leave Thanos’ side. The mission for Thanos and his followers, in large part, has to do with tracking down and acquiring the orb we saw in the Guardians of the Galaxy trailer and on display at Comic-Con (Thanos has been after it for years). That orb, as we suspect, might be one of the mighty Infinity Stones – much like the Tesseract (Cosmic Cube) and Aether are as we learned in the mid-credits button of Thor: The Dark World.

Infinity Gauntlet featured in ‘Thor’

Come time for The Avengers 3, which debuts after a series of Phase 3 films we know little of (outside of the already-confirmed Ant-Man and Captain America 3), Thanos might be headed to Earth to collect some of the missing stones yet to be introduced and begin piecing together the Infinity Gauntlet – an artifact that when fused with the six gems gives him godlike power over the universe. That’s something Marvel Studios president of production Kevin Feige teased when we spoke with him about Thor 2. All along, Feige has been teasing Thanos as a long-term villain, and part of the Phase 3 buildup.

We don’t know if this is confirmation that the Guardians of the Galaxy will show up on Earth in The Avengers 3 or if the events in that film lay the foundation for whatever happens in the third Avengers, but Marvel always plans ahead and always uses their other mediums to highlight characters and stories from the films before they release. We see it in the books all the time, with Thanos getting a lot of attention recently, much like Guardians of the Galaxy got relaunched and put in the spotlight around the announcement of the movie. And wouldn’t you know it, the Guardians just met The Avengers in the animated series Avengers Assemble for the first time:

Will Guardians of the Galaxy get a sequel in Phase 3 before The Avengers 3 ends that chapter of the MCU? Or will it launch spinoffs as Disney CEO Bog Iger suggests could happen should GOTG prove a success at the box office? Black Widow (Scarlett Johansson) wasn’t kidding when she said at the end of Captain America: The Winter Soldier that we’re going to need heroes.

“Because you need us. Yes, the world is a vunerable place, and yes, we all make it that way. But we’re also the ones best qualified to defend it. So if you want to arrest me, arrest me. You know where to find me.”

More: Marvel Plans Ahead All The Way To 2028

Captain America: The Winter Soldier is now in theaters, Guardians of the Galaxy opens August 1, 2014The Avengers: Age of Ultron on May 1, 2015, Ant-Man on July 17, 2015, and unannounced films for May 6 2016, July 8 2016 and May 5 2017.

Follow Rob on Twitter @rob_keyes for your Marvel movie and TV news!

Sources: BloombergEW (via Guard the Galaxy) (2)