Captain Marvel #33 (Marvel, 1974)

An early appearance of Thanos and first cover to feature a full body shot of the Mad Titan! "Now--I Strike--And Now--you DIE!" The imposing villain makes his presence in the Marvel Universe known by literally man-handling Captain Marvel. Years before he would begin his search for the Infinity Gems and bring them together in the all-powerful Infinity Gauntlet, Thanos wielded the Cosmic Cube, using its awesome power to defeat Mar'Vell. This issue was the culmination of the "Thanos War" storyline, which ran for over a year and established Thanos as a serious cosmic threat and one of the most dangerous villains in comics.