Thanos is one of the most interesting villains in all of Marvel comics. He has appeared in post credits scenes at the end of each Avengers movie and in one scene in Guardians of the Galaxy. In anticipation of him appearing more in Avengers: Infinity War I am posting some important background information about Thanos from the comics.
There are two groups that were created by the Celestials called Eternals and Deviants that wage war against each other. Thanos was born to two Eternals, but has a Deviant gene that makes him look deformed like the Deviants and because of this his mother tried to kill him at birth. Later on in his he became interested in death, so much so that he fell in low with the physical embodiment of death.
This caused him to search out the infinity stones to add them to the gauntlet so that he could impress death by killing a bunch of people. He was eventually able to collect them all and kill half of the universe to impress death. However he always fails in his quest, because he has a strange subconscious desire to lose.
I am excited to see how they reveal more about Thanos in Avengers: Infinity War. It will be interesting to see what parts of him they change from the comics and what parts they keep the same.