While the Marvel Universe has a lot of villains, Thanos the Mad Titan has long been considered the worst of them all. He has been the author of some of the most horrifying plots to take over the universe and rule it with an iron fist.
But as Adam Warlock once pointed out, Thanos is subconsciously afraid of success and purposefully builds avenues for his own defeat into his plans. As such, he has suffered a lot of defeats, some of them absolutely devastating to him and his reputation across Marvel Comics.
10 Deadpool Takes Death From Thanos
Being a cosmic source of malevolence and evil doesn't mean that he can't find love. And for Thanos, the object of his affections for a long time in Marvel was Lady Death. She is the physical manifestation of the abstract concept of death and Thanos was in love with her for a long time.
As one would expect, his main opponent for her affections was Deadpool. They ended up fighting over her, with Deadpool picking up the win thanks to having the power of Captain Universe. Not only did Thanos lose a fight, but he also lost the woman he loved. To Deadpool, of all people.
9 Gets Destroyed In Civil War II
Civil War by Mark Millar pitted Iron Man and Captain America against each other in a battle for the soul of Marvel's heroes. It was an epic confrontation, to say the least. Unfortunately, Civil War II by Brian Michael Bendis didn't quite live up to the high bar set by the original.
Part of the sequel's story involved Thanos attacking Earth and fighting the Avengers. The battle resulted in She-Hulk being brutally injured and the death of James Rhodes. Then, the rest of the Avengers utterly demolished Thanos. It was a pretty devastating loss for him.
8 Thanos Kills Thanos
After failing with the whole Infinity Gauntlet plan, Thanos took time off to be a farmer. That didn't last long as the Magus, Adam Warlock's evil twin, returned and started causing problems by sending everybody's evil twins after them.
That included Thanos, who ended up fighting the version of Thanos who was working with Magus. Thanos beat Thanos, turned him into a butterfly, and then ate him to regain his lost power.
7 Receives A Combined Beating From The Avengers And The Guardians
Thanos ends up in a lot of fights across the universe. It's impossible to live life the way he does and not make an impressive number of enemies. Many of them are on Earth, of course, but there are also many beings who hate him everywhere.
This time, Thanos tried to take over Earth using a Cosmic Cube. What he didn't know was that the Cube wasn't killing his enemies, just sending them to the Cancerverse. Both the Avengers and the Guardians of the Galaxy returned from that reality to savagely beat him up.
6 Mar-Vell Takes Thanos Down
When Mar-Vell came first came to Earth, he became Captain Marvel, one of the planet's greatest heroes. His eventual death sent shockwaves through the ranks of heroes across the Marvel Universe, the reverberations of which are still being felt today.
Captain Marvel and Thanos butted heads on multiple occasions. Once again, he attempted to use a Cosmic Cube to take over Earth. With the help of Drax and Mantis, Thanos was defeated and lost Lady Death's love in the process.
5 Adam Warlock Turned Thanos To Stone
If Thanos has a best frenemy, it's Adam Warlock. The two of them have worked together and faced off on multiple occasions. Some battles have led to them working on the same side while the reverse has also been the case.
One of the times that Thanos assembled the Infinity Stones involved him trapping Adam Warlock in the Soul Stone. Thanks to Spider-Man, Warlock got out and ended up turning Thanos to stone. It was one of his more embarrassing defeats.
4 Thanos Gets Arrested By The NYPD
Somehow, getting turned to stone wasn't the worst loss Thanos suffered. One would have to believe that getting arrested by the NYPD was a low point for him, and was the fault of a Cosmic Cube yet again.
He was chasing a Cube around New York when Spider-Man and Hellcat shut his shenanigans down, then turned him over to the police. Making the whole situation even worse was the fact that this was the caper when Thanos was flying around in a helicopter with his name on it.
3 Nebula Steals The Infinity Gauntlet
Possibly the most famous move Thanos pulled was using the Infinity Gauntlet to kill half of all life in the universe. It was a vain attempt to curry favor with Lady Death, a move that landed like a lead balloon.
Thanos also used his power to torture Nebula in some truly horrific ways. But he left an opening for her to take the Gauntlet and all of the power that came with it. Without question, it was one of his worst defeats because it never should have happened.
2 Got His Butt Handed To Him By Squirrel Girl
Marvel has more than few dark-horse characters who often come out of the left field and show everyone who's boss. A major one is Squirrel Girl who has victories over the likes of Wolverine and even Thanos.
Her actual battle with the Mad Titan happened off-panel but The Watcher was on hand to make two things abundantly clear. First, she was fighting the real Thanos. And second, she absolutely destroyed him.
1 Drax Ripped His Heart Out
No one else in the Marvel Universe has been more obsessed with Thanos than Drax. Born on Earth, he and his family were murdered by Thanos. Drax was resurrected and given the mission of killing the Mad Titan, a goal he doggedly pursued for a long time.
After years of trying, Drax finally got the job done when he punched his quarry's heart out from behind. It was a brutal death that Thanos did not see coming, both from a metaphorical perspective and from a literal one.