The Leader first appeared in Tales to Astonish #62 (December 1964), created by writer Stan Lee and artist Steve Ditko as the archenemy of the Hulk.

While Sterns was transporting radioactive materials, an explosive accident bombarded him with gamma radiation, which turned his skin green, abnormally enlarged his cranium and brain, and granted him a superhuman intellect that reflected his subconscious desire to be smarter than his brother.

[8][9] Renaming himself the "Leader", he forms an espionage ring to overthrow the United States federal government and enlists the Chameleon to steal high-level secrets.

[12] The Leader then switches tactics by manipulating the Hulk into helping him steal the Watcher's "Ultimate Machine", a device containing all knowledge in the universe.

[13] After obtaining the device and visualizing its contents, the Leader apparently dies of shock, with even his enhanced brain unable to comprehend the knowledge that the Ultimate Machine contains.

[20] With their help, he builds a self-sufficient society called "Freehold" in Alberta, populated with civilians dying from radiation poisoning.

[24] When Banner is dying from ALS, the Leader summons the Hulk to give him a cure in exchange for witnessing his ascension from the mortal plane.

However, when Ross discovers that the Red She-Hulk is his daughter, he drains the gamma radiation from the Leader's body, depriving him of his super-intelligence and reverting him to his human form.

[34] Initially forced to work for Ross's Thunderbolts, the Red Leader manages to escape and begins to rebuild his criminal empire, but is recaptured.

[35] After somehow escaping from Mephisto's captivity, the Red Leader is tracked down by "Doc Green", an ingenious and ruthless new personality of the Hulk, and is deprived of his powers.

However, the Red Leader had previously taken possession of an artificial intelligence created by Banner, which restores his intellect, powers and original green-skinned complexion.

[36] In the miniseries Hulkverines, the Leader is shown to be detained at Shadow Base Remote Facility 43B using Big Bob's Lumber Lounge in Akron, Ohio as a front.

The Leader and Dr. Alba unleash the mutated Hulk and Wolverine on Shadow Base Auto-Op WMD Facility BX91 in Central, Ohio using Green Energy Corp as a front.

His higher brain functions, including pattern recognition, information storage/retrieval and logical / philosophical structuring have been enhanced to inhuman levels.

He also has total recall of every event he has witnessed since the accident that transformed him and can calculate possibilities and outcomes so accurately that it borders on predicting the future.

He has created technology that is beyond human ability, including vehicles, weaponry, computers, laser pistols, pulse weapons and kinetic gauntlets, and is particularly adept at genetic engineering and manipulating radiation for many nefarious purposes.

The Leader has created an army of synthetic henchmen at his disposal called the "Humanoids" that have served him throughout his career of world domination, mainly as bodyguards, soldiers and laboratory servants.

They have versatile programming capacities to allow them to perform any task, do not tire, talk or need sustenance and have elastic-like bodies that make them immune to blunt impacts.

[53] The Leader appears in several drafts for unproduced scripts for a Hulk film, including one penned by John Turman seeing him renamed Edward Leder.

[57][58] Dr. Samuel Sterns appears in media set in the Marvel Cinematic Universe (MCU), portrayed by Tim Blake Nelson.