Thanos

"The only matter I do not take seriously, boy, is you. Your politics bore me! Your demeanor is that of a pouty child. And apparently you alienated my favorite daughter, Gamora. I shall honor our agreement, Kree, if you bring me the orb. But return to me again empty handed and I will bathe the star-ways with your blood."

- Thanos

Thanos is an extraterrestrial Eternal warlord who allies himself with Loki and Ronan the Accuser. He is seeking the Infinity Stones and testing the heroes that protect Earth.

Guardians of the Galaxy Prelude
Thanos took in and raised Nebula and Gamora. After finding the location of The Orb, he sent Nebula after it, but she failed as she fell on a trap. After Gamora found Nebula in the trap, Thanos told Gamora to leave Nebula behind.

Thor: The Dark World Prelude
Frigga, the adoptive mother of Loki, observed the meeting between Loki, Thanos and The Other.

The Avengers
Thanos is a powerful alien, a warlord who rules over a dead dimension. He allies himself with the exiled Loki Laufeyson, providing him with the deadly army of the Chitauri, who will help him in conquering Earth, in exchange for the Tesseract, a powerful energy source.

When Loki has arrived on Earth, Thanos is contacted by him, and the Other warns the God of Mischief of the price of failure and reminding him to not question the will of the master, declaring that if he fails in defeating the Earthlings, Thanos will make him know a new kind of suffering.

When eventually Loki is defeated, the Other complains that the Earth's inhabitants are not as weak as they were supposed to be and declares that challenging the Earth's heroes would be to court Death. To this, Thanos simply smiles.

Guardians of the Galaxy Prelude
"Of course, I always was a man with an eye for a bargain. I may be able to help. But there is always a price, is there not?"

- Thanos to Ronan Sometime later, Thanos brokered a deal with his old ally, Ronan of the Kree, promising to lend a fraction of his forces in a genocide against the Xandarians in exchange for aiding in the search for the Orb. Ronan discovered the true location of the Orb on the planet Morag and attempted to deliver it to Thanos, but an unexpected turn of events ensued and the stone fell into the possession of human pilot Peter Quill and his allies. Unwilling to be denied another stone, Thanos ordered Ronan to pursue Quill and recover the stone, sending Nebula to aid the Kree in his pursuit.

Guardians of the Galaxy
"The only matter I do not take seriously, boy, is you. Your politics bore me. Your demeanor is that of a pouty child. And apparently, you have alienated my favourite daughter, Gamora. I will honour our agreement with the Kree, if you bring me the Orb. But if you return to me empty handed again... I will bathe the starways in your blood."

- Thanos, threatening Ronan over their initial agreement.

Upon learning of Gamora's imprisonment in the Kyln, Ronan was called to Sanctuary by The Other, who he quickly killed after a brief argument. Ronan then proceeded to call Gamora a traitor, prompting Thanos to finally speak and intimidate Ronan into retrieving the Orb and Gamora, over Ronan's life.

After Ronan retrieved the Orb, he immediately contacted an enraged Thanos, informing him that he was out of the deal, promising that he would destroy Xandar himself before coming for the warlord himself. To this, Thanos simply responded by cutting the transmission in anger.

Avengers: Age of Ultron
"Fine, I'll do it myself."

- Thanos

Thanos opened a vault to a stoneless Infinity Gauntlet and put it on his left hand deciding he will collect the Infinity Stones and destroy the Earth himself.

Avengers: Infinity War
To be added

Avengers 4
To be added

Character traits
Thanos is one of the most powerful warlords in the universe. Korath also says that Thanos is the most powerful being in the universe. Ronan the Accuser shown visible signs of fear in his presence. He has little to no regard for his followers, showing no empathy when Ronan killed The Other and referring to Gamora as his "favorite daughter" even with Nebula present. He inspires no love, as he is despised by his own "daughters" Gamora and Nebula. He is also manipulative and untrusting, sending Ronan to retrieve the Orb for him and not telling him that it contained an Infinity Stone. Thanos is now hunting for the Infinity Stones himself.

None of Thanos powers are actually shown (yet). Thanos was able to threaten a god such as Loki and command the powerful army of the Chitauri unchallenged. Thanos threatened to bathe the starways in Ronan's blood if he failed to deliver The Orb. When Ronan was about to betray Thanos and use the Orb for himself, Ronan was confident enough that he could kill Thanos with the Power Stone. Nevertheless, Thanos displayed no sign of concern after Ronan threatened him.

Powers and Abilities
To be added

Relationships

 * Death - Love interest and ally.
 * Loki Laufeyson - Ally.
 * The Other - Vizier; deceased.
 * Chitauri - Subordinates.
 * Leviathans - Subordinates.
 * The Avengers - Enemies.
 * Guardians of the Galaxy - Enemies.
 * Gamora - Adopted daughter turned enemy.
 * Ronan the Accuser - Ally turned enemy.
 * Korath the Pursuer - Ally turned enemy.
 * Nebula - Adopted daughter turned enemy.

Appearances/Actors

 * Marvel Cinematic Universe (3 films)


 * The Avengers (First appearance) - Damion Poitier
 * Guardians of the Galaxy - Josh Brolin (voice/performance capture) and Sean Gunn (motion capture)
 * Avengers: Age of Ultron - Josh Brolin
 * Avengers: Infinity War - Josh Brolin
 * Avengers 4 - Josh Brolin
 * Marvel Cinematic Universe (3 comics)


 * Thor: The Dark World Prelude
 * Guardians of the Galaxy Prelude
 * Guardians of the Galaxy Prequel Infinite Comic

Behind the scenes

 * Thanos' presence in the movie was kept top secret from the production until the release of The Avengers.
 * Damion Poitier was credited as playing "Man #1" in order to hide the identity of Thanos at the end of the film. It was later publicly announced after the film's release.
 * Kevin Feige has said that Thanos will likely be played by a different actor in future films; this has been confirmed with the casting of Josh Brolin as the voice of Thanos in Guardians of the Galaxy, Avengers: Age of Ultron and possibly a third Avengers film, with a physical presence being provided by motion capture.
 * Joss Whedon has said that Thanos will play a major role in the "Final Act", referring to Avengers 3 as a whole, stating: "Well, Thanos is more powerful. He is so powerful he is not someone you can just try out and punch him. Like he did in the comics, you want him to threading through the universe and to save the big finale for ‘the big finale’. He is definitely a part of what I have got going on. The thing about the Avengers is that they are very powerful but not very stable. So, there will definitely be some people that will shake them up in the next installment (AoU)."
 * Kevin Feige has reiterated his statements about Thanos shaking things up for The Avengers, and what his role in the overall scheme of things in the Marvel Cinematic Universe: "If you remember we had a tag scene in Thor: The Dark World where Benicio Del Toro showed up for the first time as The Collector, so that was our way of saying the Guardians and the other Marvel characters inhabit the same reality and the same universe. In particular, there's a villain in this film [Guardians], that comic fans know as Thanos, that moviegoers will begin to learn more and more about in the coming years. He appeared at the very end of the first Avengers film, when he turned into camera and smirked, and we realised he was the person behind the alien army that Loki teamed up with to terrorise New York City, and that the Avengers had to fight. going on to say "We see him again in this movie [Guardians], we learn a little bit more about him in this movie, and he - and his band of followers - is the biggest piece of connective tissue that will eventually lead us back into Avengers films in the future."
 * Kevin Feige had this to say about Brolin's inclusion as Thanos, as well as Brolin's excitement about the role:  "We reached out to him and it was one of those things that does not happen all the time but when it does it’s very nice, where he was totally intrigued. He was a fan of what we did, he met with Jeremy Latcham in a hotel in London and learned about the characters a little bit. I spoke to him on the phone a few times. We ran it by James who loved it, ran it by Joss who loved it because Thanos is in this universe because of Avengers. Then we shot him and recorded for it." while also saying thos about his role in Age of Ultron: "We knew he was going to be in this movie (Age of Ultron). We wanted somebody to be more than just the voice. Josh did the performance as well. We were looking at a wish list of, “Wouldn’t it be great if names,” and his name was on it. And you look at his face and the performances he gives, he could be Thanos without any effects. He has that kind of face and that kind of gravitas to it."
 * James Gunn's brother Sean was a stand-in during filming, and Josh Brolin did both motion capture and voice for Thanos.
 * Josh Brolin's role in Guardians of the Galaxy and Avengers: Age of Ultron was uncredited.
 * Thanos' look was changed for Guardians of the Galaxy; his skin was changed to a lighter lavender, and his eyes were darkened. His gloves were also removed, instead replaced with armored gauntlets. This was most likely because his initial appearance was more of an early model just for the post-credits scene, explaining his more elaborate appearance for a more prominent role.
 * In an interview, Josh Brolin expanded on Thanos' relationship with Death, and confirmed that Death will be portrayed as a woman in the Cinematic Universe: "His relationship with Death, who is actually the woman, I love that. You can take Sin City (in which Brolin plays a man obsessed with a dark-hearted woman) and pump it full of steroids, and then you have Thanos. I like that he’s motivated by that — not just motivated by destruction or death or this or that. He’s motivated by a very identifiable, human trait.”

Trivia

 * In the comics, Thanos has no relationships with Loki Laufeyson nor the Chitauri, but he's nevertheless one of the historical foes of the Avengers.
 * In the comics, Thanos is the master of the Infinity Gauntlet, which he used in the eponymous series in an attempt to court Death. He was also one of the many users of the Cosmic Cube.
 * Thanos is one of few antagonists not to be killed in their debut appearance, others being The Other, Loki, Justin Hammer, The Abomination, Thaddeus Ross, Georges Batroc, Winter Soldier, Brock Rumlow, and possibly Johann Schmidt/Red Skull.
 * Rhomann Dey mentions Thanos as "The Mad Titan", as he is called in the comics.
 * According to Korath, Thanos is the most powerful being in the universe. Ronan suggests that he could kill him through use of the Orb, but whether he truly could is unknown.