Up till the end of Phase 2 of the MCU, Thanos has been nothing but a myth. Some awkward, giant purple dude that likes to float around in space gloating about how powerful his chin is.
But he will more than likely have the last laugh, as will Marvel when they coin the phrase "slow and steady wins the race," in regards to Thanos' deployment in the MCU. In the comics, the "Chin That Floats" has been a constant thorn in the side of the universe's greatest heroes on numerous occasions, even defeating and murdering many.
So in order to see what all the fuss is about, and ready the full-fat entrance of who, legit, could be one of the greatest adversaries cinema has ever seen, check out these fairly lofty reasons why the heroes of the MCU should fear the Mad Titan:
Thanos: Deadliest Being in the Galaxy
Parents - Mentor & Sui-San (Leaders of the Titans)
Abilities - Superhuman strength, durability, and endurance, energy manipulation, telekinesis, teleportation, longevity, amongst many others...
Thanos is a member of a race of beings known as the Titan Eternals. Born on Titan, the sixth of Saturn's moons, Thanos was considered a mutant of the species after coming into contact with the Deviant gene, rendering his skin purple and evolving his already fantastical array of abilities, such as the ability to absorb and manipulate cosmic energy.
Shunned by his peers due to his mutant abilities and jealous of the adulation of his brother Eros, the young and solemn Thanos befriended Mistress Death - the two later becoming lovers. Under Death's tutelage, he grew stronger, wiser and more bereft of empathy, and, due to his dabbling in black magic - an act forbidden on Titan, was exiled by his father. Thanos later returned to Titan to destroy the moon and his people, accidentally killing his mother in the process.
He isn't afraid of wiping the floor with his children too. Thanos is known to have various sprogs around the galaxy, and eliminating them on his destructive jaunts through the stars. One of the most the most famous of his children Gamora, was raised by him from a young age, and he hid his true evil nature from her by brainwashing the poor green kid.
Later, when the veil was finally dragged off, Gamora attempted to kill Thanos, and you can kinda guess how that turned out. Not well for Gamora basically. His son Thane, an Inhuman, somehow managed to beat his father by trapping him in a state of "living death."
2. His Abilities
Besides being the most powerful of the Eternals and a mutant, Thanos has cybernetic enhancements embedded in his body, which make him virtually the strongest of characters in the Marvel universe, beating the likes of Hulk, Thor and Silver Surfer on multiple occasions.
He's a veritable genius too, rivaling - or even besting - Reed Richards, Tony Stark and Bruce Banner.
3. That Damn Gauntlet
In Marvel's comic lore, the Infinity Gauntlet is a weapon of outrageous power which was the source of, possibly, the comic universe's greatest tragedy.
The source of the Gauntlet's power comes from the 6 Infinity Stones - Time (green), Soul (orange), Power (purple), Space (blue), Mind (yellow) and Reality (red). Whosoever gets their hands on all 6, ostensibly attains dominion over the entire universe.
In the comics, Thanos managed to wipe out pretty much half of the universe, slaying numerous heroes as he went. The most notable deaths including a lot of the X-Men including Wolverine and Cyclops, Scarlet Witch, Captain America, Thor and Adam Warlock. He even managed to take down Galactus and the Stranger.
All that without even touching upon the strife with Cosmic Cube and Heart of the Universe, and it's a wonder why Marvel is being so careful when utilizing him. He hopefully will turn out to be one of the greatest supervillains cinema has seen.
He doesn't mess about, ol' prune chin.
What do you think?
(Source: Wiki, Comic Vine)