After the Fantastic Four stopped the Skrulls' attempted invasion of Earth, Skrull Emperor Dorrek invested vast resources into creating a superbeing of his own. K'lrt, a decorated soldier and warrior of the Skrull empire, was chosen to undergo a process that endowed him with all the powers of the Fantastic Four, except, when powered by an interstellar beam, far stronger. When the Super-Skrull first confronted the Fantastic Four, he bested them with their own abilities until Mister Fantastic identified the power source beamed from the Skrulls home planet and created a jamming device, depriving the Super-Skrull of his powers. Then the Invisible woman tripped him into a crater and the Human Torch melted the rock around it to seal him in. Realizing their champion's predicament, the Skrulls developed a stronger source of power and beamed it to him. Re-powered, the Super-Skrull, disguised himself as Doctor Franklin Storm, the father of the Invisible Girl and the Human Torch, and again attacked the Fantastic Four. He called himself the Invincible Man, and claimed that he had received his powers in the Skrulls' prison laboratory. But Mr. Fantastic soon discovered the truth and threatened the Skrull homeworld with a fight to the death with the Super-Skrull and a direct atomic attack on their homeplanet. The Skrulls recalled the Super-Skrull and sent Dr. Storm back, although they first booby-trapped him with an explosive in an attempt to destroy the Fantastic Four. Storm, however, threw himself on the floor and took the brunt of the explosion to save his family and their friends, killing himself.

His repeated defeats at the hands of the Fantastic Four allowed the Super-Skrull to fall out of favor with his government. Despite a second chance against the thunder Thor , the Super-Skrull was exiled.However, due to the loyalty to his race and his extreme power levels, the Skrulls have usually found they have need of the Super-Skrull, recalling him to service time and again. For example, Dorrek once hoped the Super-Skrull would the Kree Captain Marvel), disrupting the Kree from their surveillance of Earth, but Captain Marvel turned Kl'rt's power against him. Another time, he was drafted into the then-ongoing Kree-Skrull War, fighting the Avengers but hoping to take advantage of the war to increase his own political standing. This time, he was sent into permanent exile for treason. Working as a free agent, the Super-Skrull became an agent for Thanos the mad Titan, running once more into Captain Marvel. This time, his defeat left him stranded on Earth without interstellar transportation. Hoping to power a starship and flee the planet, he tried to steal the Cavourite crystal but was confronted by Ms. Marvel and Spider-Man. The Super-Skrull routed the two, but when he captured the crystal, its energies interfered with those of the interstellar beam that boosted his powers-- he found himself teleported to the Skrull throneworld. Unfortunately, he could never regain his physical form.

The throneworld soon fell victim to Galactus, and the process of the planet's destruction send the Super-Skrull's disconnected form back to Earth, where it became trapped in the Van Allen Radiation Belts. Eventually, a group of scientists, including Dr. Walter Langkowski, a.k.a. the hero Sasquatch, made contact with the Super-Skrull's atoms with their equipment, inadvertantly allowing the Super-Skrull to reincorporate. The Super-Skrull's elation at being free was tempered with the fact that he was now physically dying. As a result of his entrapment within the radiation belts, he had developed a form of leukemia. Sasquatch battled the rampaging Skrull but was ultimately forced to return him to his discorporate state and return it to the Van Allen Radiation Belts once more.

During his time of incapacitation, the Skrulls lost their natural shape-changing powers and their empire was decimated into factions. (In fact, K'lrt's wife R'Kll was the assassin who killed the Emperor Dorrek.) One of the self-proclaimed "Empresses" of the empire's remnants, S'byll, tricked the Silver Surfer into using his power cosmic to re-form the Super-Skrull in order that they may aid her fleet in battle against the Badoon. This act threatened to escalate a new Kree-Skrull war, and the Super-Skrull convinced the Surfer to use his power cosmic to help him catalyze the latent shape-changing powers in S'byll's genetic structure. The two were able to awake the full power of a shape-changing Skrull in S'byll as well as to give her the ability to rekindle the shape-changing powers of others of her race. S'byll was sure that this ability would grant her support for her Empress-ship and allow the Skrulls to defy the Kree's genocidal efforts against the Skrulls. K'lrt stayed on as S'byll's champion, enjoying unparalleled fame as a great hero of the Skrull worlds.

Shortly after, the enigmatic Stranger appeared and tried to add S'byll to his collection. The attempt was foiled when the pirate Captain Reptyl arrived on the scene and traded his entire pirate crew for her. In return for her freedom, he asked to become a privateer in her cause, and S'byll, happy to find a new ally, accepted his service. Enraged, K'lrt dueled with Captain Reptyl for the honor of being S'byll's consort and the Warlord of the Skrulls. K'lrt lost, and was believed slain, left to drift in space. In fact, the Super-Skrull did not die, but managed to find his way back to Earth where he decided to remain hidden until he could receive orders from a legitimate heir to Emperor Dorrek.

At one point, the Super-Skrull duplicated the likeness of Danny Rand, a.k.a. Iron Fist, fully assuming his identity in order to use the Rand Corporation and gain economic control of the Antarctic paradise known as the Savage Land. This conflicted with the plans of another company, Oracle Inc., owned by Prince Namor the Sub-Mariner. Namor, Namorita, and Misty Knight confronted Super-Skrull, who, with his plans ruined, abandoned Rand's identity and fled. (The assembled heroes set out on a search for the real Danny Rand, eventually freeing him from the alien H'ylthri.)

During his time of hiding, he appropriated the identity of Lon Zelig, a master of disguise, and he quickly gained renown in Hollywood. Eventually, he was targeted for assassination by other Skrulls, who believed K'lrt to be a living representative of an old regime and a dangerous potential menace. The Skrulls tricked the Human Torch into fighting alongside them, but K'lrt defeated the attempt and revealed the truth to the Human Torch before disappearing once more.

The Super-Skrull was impressed into serving a Skrull faction led by the Intelligentsia, a Skrull version of the Kree's Supreme Intelligence. Although he apparently bristled at her leadership, he followed one of her orders to kidnap Kelly, a girl on Earth who held a special connection to the nexus of all realities. This first brought him into conflict with Captain Marvel over her fate, but Kl'rt kidnapped her, rather than killing her as was ordered, and returned to Intelligentsia with her. Hoping to stage a coup, with the girl's powers, the Super-Skrull again fought off Captain Marvel, but Kelly instead turned her power on herself, negating her abilities, rendering the whole thing moot. The Super-Skrull was never seen working with the Intelligentsia again. He is a character in the Marvel Vs. Capcom series, and Fantastic Four series. Super Skrull, born Kl'rt, is a member of the Skrull race and a villain of the Fantastic Four.