Since his debut in the Marvel Cinematic Universe, Thanos' appearance has changed significantly, and understandably so. Six years after his first appearance in The Avengers, we finally got quite a different look at the Mad Titan in action in Avengers: Infinity War, in what many thought would be his final look for the Infinity Saga.

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But as is the case with most comic book movies, just like heroes, villains also get upgraded looks in sequels, whether that's to their physical form or in the shape of their battle gear. With that in mind, let's look at how Thanos' look has evolved as he prepares to take on Earth's Mightiest Heroes a second time in next month's Avengers: Endgame.

THE AVENGERS (2012)

Thanos in post credit of The Avengers

Calling Thanos' cameo in the post-credits of The Avengers a tease would be quite an understatement. When The Other spoke to him about Earth being difficult to invade, we mostly saw him from the back on his throne. However, the final scene showed his face with a wry smile, foreshadowing the hunt for the Infinity Stones.

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We only saw from the shoulder up, with Thanos' side-profile strongly resembling the character's then-actor, Damion Poitier. He had a more rounded nose, glowing blue eyes and his face's coloration was a deep, dark purple. His armor remained obscure, apart from the pointed, golden shoulder pads. Other than that, it was tough to tell how he really looked, as the lighting was dark, which even resulted in his armored wrists and exposed hands not matching his face's skin tone at all. That said, the main selling point was his signature jagged chin, which gave the overall impression he would look like he did in the comics.

GUARDIANS OF THE GALAXY (2014)

Thanos made his speaking debut two years later with Josh Brolin doing performance capture for the role. Director James Gunn had his brother, Sean, act as the stand-in for the character, but otherwise, the impression we were left with was truly an imposing one that felt like Brolin was, indeed, over seven feet tall.

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We now saw his entire body, and what stuck out most was that his purple skin was significantly lightened. It didn't sit well with some fans, but the studio made it clear it was a work in progress. As for his eyes, they were still vibrant and ethereal, but because he was lighter, their glow didn't pop as much. This did, however, highlight his facial scars more.

Ultimately, leeway was given because of how impressive Thanos looked in the full body shot. His elaborate, fully-plated armor from head to toe mirrored the comics' costume closely, with a narrow "T" shaped in gold on his chest flowing into his shoulder pads to truly craft an intimidating visual.

NEXT PAGE: Infinity War's Thanos Makes a Glorious, Insidious Entrance

AVENGERS: AGE OF ULTRON (2015)

The villain subsequently appeared in a post-credits sequence here, opening a chamber and putting on a non-canon Infinity Gauntlet, muttering: "Fine. I'll do it myself." His eyes and skin tone were exactly what we saw in GotG, and he maintained the same layered armor, helmet and pointed shoulder pads.

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There was a slight tweak, though, as Thanos' voice sounded a bit more like Brolin's, as he came off whimsical despite his frustration at not getting his Infinity Stones. As he slipped the Gauntlet on, it felt like a slightly different aesthetic, as opposed to him just sitting, barking orders. Seeing Thanos moving swiftly in motion like this definitely helped create a sense of dread, but overall, there wasn't any big evolution over the year.

AVENGERS: INFINITY WAR (2018)

Avengers Infinity War Thanos

When we finally saw the Mad Titan in all his butt-kicking glory, it was quite a spectacle. What was most noticeable was that his armor was less bulky and more sleek. There was also a more streamlined look to his helmet, which made Thanos look more battle-ready, as opposed to the past versions where his costume felt decorative. He now appeared more practical, but still with the influence of the books.

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His arms weren't armored up fully, though, as he sported gladiatorial wrist pads. This allowed us to see his muscles, which popped even more when Thanos resorted to his casual wear. We witnessed this when he spoke to Gamora about his plan back at his lair, and also later when he donned a more casual look: a regal vest, long military pants, knee pads and boots. It seemed like an odd choice, but this lax aesthetic was because the Russo brothers wanted to illustrate he was on a spiritual journey, not a warpath.

AVENGERS: ENDGAME (2019)

We haven't seen much of Thanos in trailers, bar a fleeting glimpse of him in his field. Quick shots show he's thrown his armor on the scarecrow, and in a magazine cover, he's wearing his Infinity War costume. It's not expected that there'll be many upgrades or improvements, for continuity's sake. Thus far, that seems to be the case.

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His face and overall mean demeanor also indicates there hasn't been much brushing up on the CGI, not that any was needed in the first place. We can also spot the Infinity Gauntlet, although this image doesn't really indicate if it's busted up, as it was at the end of the last movie. It should be in a somewhat derelict state in Endgame. Also, we don't know if it's hiding a mangled hand after the effects of the snap. However, if there are any changes to Thanos' war suits or physical appearance, it should come as no surprise the Russos are keeping them secret for the return fight against the Avengers.

Directed by Anthony and Joe Russo, Avengers: Endgame stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Jeremy Renner, Don Cheadle, Paul Rudd, Brie Larson, Karen Gillan, Danai Gurira, Benedict Wong, Jon Favreau and Bradley Cooper, with Gwyneth Paltrow and Josh Brolin. The film arrives April 26.