Thanos is one of Marvel's most popular villains, but more than that, an argument can be made that Thanos is Marvel's greatest villain.
Thanos is a villainous legend, having become one of the most popular villains in the world due to his appearances in the Marvel Cinematic Universe.
Creator Jim Starlin introduced Thanos in Invincible Iron Man #55, making him one of the premiere cosmic villains in the Marvel Universe.
Thanos’s nihilism and desire for ultimate power have made him an enemy of every champion of life, earning him the fear and respect of every hero in the Marvel Universe.
Marvel has created some of the greatest villains ever, but some argue that Thanos stands out as the greatest Marvel villain.
Thanos has become one of the most popular villains in the world because of his appearances in the Marvel Cinematic Universe.
Author's summary: Thanos is Marvel's greatest villain due to his legend and impact.