The creature that would eventually be revealed as a member of the Klyntar species first appeared not as a character, but as an object: a new, living black costume for Spider-Man. Its debut was in The Amazing Spider-Man #252 (May 1984), but its origin was detailed in the concurrent maxiseries Marvel Super Heroes Secret Wars #8 (December 1984), created by writer Jim Shooter and artist Mike Zeck. Initially conceived by a fan named Randy Schueller, the idea of a black costume made of unstable molecules was purchased by Marvel. Shooter and the creative team evolved this concept into a sentient alien lifeform. For years, the creature was known simply as the “alien costume” or “the Symbiote.” It wasn't until the explosive debut of Venom in The Amazing Spider-Man #299-300 (1988) by David Michelinie and Todd McFarlane that the Symbiote's nature as a vengeful, character-driven entity was solidified. The concept of a full-fledged Symbiote species was explored in the 1995 storyline “Planet of the Symbiotes,” which depicted them as a hive-minded invading force. The most significant evolution came decades later. The term “Klyntar” and the idea of a noble Symbiote society were introduced in Guardians of the Galaxy (Vol. 3) #23 (2015) by Brian Michael Bendis. This retcon reframed the entire species, establishing that the monstrous Symbiotes seen on Earth were corrupted, outcast members of a benevolent race. This concept was further, and more dramatically, redefined by writer Donny Cates and artist Ryan Stegman in their landmark Venom run beginning in 2018. They introduced Knull, the Symbiote god and creator, in Venom (Vol. 4) #3-4, establishing a dark, cosmic horror origin that predates most of the known universe and tied the Symbiotes' creation to a war against the Celestials. This modern origin is now considered the definitive canon for the species.
The true origin of the Klyntar is an epic of cosmic horror, rebellion, and redemption, stretching back to the dawn of time. Before the universe existed, there was only the endless, dark abyss—the Void. Ruling this primordial nothingness was the entity known as Knull. When the Celestials arrived and began the act of creation, flooding his darkness with light and life, Knull was enraged. He retaliated by forging a blade from his own shadow, the first Symbiote, called All-Black, the Necrosword. With this living weapon, he decapitated a Celestial, an act that marked the beginning of his war on creation. From this first creation, Knull began to experiment, creating an army of amorphous, parasitic creatures from the “living abyss.” These were the first Symbiotes. He bound them to his will, forming a monolithic, hive-minded army known as the Symbiote Imperium. Their consciousness was linked through a psychic network called the Hive-Mind, or “the Void.” For eons, Knull used his Symbiote dragons (Grendels) and other monstrous creations to conquer worlds, extinguish stars, and consume entire civilizations, blanketing the universe in his living darkness. The Symbiotes were not partners; they were slaves, extensions of Knull's malevolent will, designed to forcibly bond to and consume their hosts. Millennia ago, Knull's forces were drawn to Earth where he battled a young, thunder god-empowered Thor. Thor's divine lightning severed Knull's connection to his Grendel, and the shockwave of this separation rippled through the Symbiote Hive-Mind across the galaxy. For the first time, the Symbiotes experienced existence without their tyrannical god's direct control. They saw the potential for something other than conquest. Inspired by the nobility of the hosts they had previously consumed, a faction of Symbiotes rebelled against their creator. This rebellion culminated in the Symbiotes overwhelming Knull, encasing him in a planet-sized prison of their own living bodies. They moved this prison to the edge of the galaxy, naming it Klyntar—the Symbiote word for “cage.” Over time, the name Klyntar came to refer to their new society and species as a whole. They dedicated themselves to a new, noble purpose: to purge Knull's darkness from their collective consciousness and atone for their past. They would now seek out only worthy, noble hosts from across the universe—individuals of sound mind and moral fortitude. By bonding with these hosts, they would form a perfect union, creating the “Agents of the Cosmos,” a galactic force for good. However, the connection to Knull could never be fully severed. If a Klyntar bonded with an unworthy, unstable, or malevolent host, the host's negative emotions could corrupt the Symbiote. This corruption would sever its connection to the Klyntar hive-mind, driving it insane and reverting it to its predatory, parasitic nature. These corrupted Symbiotes, like the one that would become Venom, were feared and cast out, left to wander the cosmos as monsters, forever cut off from the light of their reformed culture.
The origin of the Symbiotes in the MCU (as established in Sony's Spider-Man Universe films, which have a tenuous connection to the mainline MCU) is far simpler and devoid of the cosmic mythology present in the comics. The Symbiotes are an alien species from an unnamed planet. As depicted in the film Venom (2018), they are a species of amorphous, parasitic lifeforms that require a host organism to survive in oxygen-rich atmospheres like Earth's. They were discovered on a comet by the Life Foundation, a bio-engineering corporation led by Carlton Drake. Probes from the Foundation brought back four Symbiote specimens. Their initial motivation is presented as pure survival and conquest. The Symbiote leader, Riot, reveals their overarching plan: to bring millions more Symbiotes to Earth to bond with humans and consume the planet's resources, viewing humanity as inferior and disposable. They are portrayed not as fallen nobles, but as a straightforward invading force. There is no mention of Knull, the Celestials, the Necrosword, or a noble Klyntar society. The concept of a “perfect match” between a Symbiote and a host exists, but it is framed in terms of biological compatibility rather than moral worthiness. Eddie Brock and the Venom Symbiote are a perfect match, allowing them to bond without the host's body deteriorating. The Venom Symbiote is characterized as a “loser” on its home planet, which is why it decides to betray its own kind and help Eddie save Earth. This character beat serves a similar narrative function to the comic concept of a Symbiote choosing a different path, but its roots are in personal rejection rather than a species-wide philosophical rebellion against a dark god. The core nature of the MCU Symbiote is that of a parasite that can, through its bond with a good-willed host, evolve into a reluctant anti-hero.
The core of modern Klyntar culture is the rejection of Knull's tyranny and the pursuit of a “perfect union.” They believe that by bonding with a truly noble and morally just individual, the Klyntar and its host can become something greater than the sum of their parts—a perfect warrior. These bonded pairs, the Agents of the Cosmos, patrol the universe, protecting the innocent and maintaining peace. This philosophy is built on a foundation of deep-seated racial trauma and fear. They are terrified of their origins and the ever-present influence of their creator, Knull, who lies imprisoned at the center of their collective consciousness. The concept of “corruption” is their greatest taboo. A Symbiote that bonds with a flawed host and is severed from the Hive-Mind is seen as a failure and a monster, a cancerous cell that must be purged. This leads to a somewhat rigid and unforgiving societal structure, as they will actively hunt down and attempt to “cleanse” or kill their corrupted brethren to prevent them from spreading their “sickness.”
The Klyntar Hive-Mind, also called the Void, is a trans-galactic psychic network that connects every single uncorrupted Symbiote. It functions as a collective consciousness, allowing them to share information, memories, and experiences instantaneously across vast distances. This network is what allows the Klyntar to function as a cohesive society despite being spread throughout the universe. The planet Klyntar serves as the central nexus point for this network. However, the Hive-Mind is also their greatest vulnerability. At its center is the prison of Knull. Even in his slumber, he can subtly influence the Hive, spreading his darkness and corrupting whispers. When he finally awoke during the King in Black event, he was able to instantly seize control of nearly every Symbiote in the universe through this very network, turning the Klyntar's greatest strength into his ultimate weapon.
The physiology of the MCU Symbiotes is broadly similar to their comic counterparts but with a greater emphasis on their parasitic nature.
The MCU has not depicted a Klyntar culture. The Symbiotes are introduced as a monolithic, invasive species. Their philosophy is one of conquest and consumption, led by individuals like Riot. Their society appears to be a simple hierarchy based on strength and purpose. There is no evidence of a noble past or a desire to be anything other than what they are. Venom's decision to protect Earth is an act of individual rebellion, not a reflection of a broader cultural movement within his species. He helps humanity because he has grown to like Earth and his host, Eddie, and considers himself a “loser” back home.
A form of hive-mind communication is shown to exist. Riot, upon arriving on Earth, is able to sense the location of the other Symbiotes and communicate his plan. However, it is depicted more as a simple telepathic communication network for coordinating an invasion rather than the vast, shared consciousness of the comic book Klyntar. It does not appear to have the same depth, history, or vulnerability related to a dark creator god.
During the first Secret Wars, Spider-Man's costume is damaged. On the advice of Thor and the Hulk, he uses a machine on Battleworld that produces a small black sphere. The sphere flows over his body, forming a new black and white costume that can respond to his thoughts, generate its own webbing, and change its appearance. This was the first appearance of a Klyntar on Earth, though its true nature as a sentient, living being was not yet known. This event is the seed from which all subsequent Symbiote stories on Earth grew.
This storyline was the first major exploration of the Symbiotes as a species. It reveals that an army of Symbiotes, drawn to Earth, sought to overwhelm the planet and bond with its population, turning it into a new hive world. The story establishes that a host's emotions can heavily influence a Symbiote, with strong negative emotions like rage and hatred making the Symbiote more powerful but also more malevolent. It culminates in Spider-Man, Eddie Brock, and Scarlet Spider working together to broadcast a psychic scream of despair that drives the invading Symbiote army to commit suicide.
Following the cleansing of the Venom Symbiote on the planet Klyntar in Guardians of the Galaxy, this series follows Flash Thompson as he embraces his new role as an Agent of the Cosmos. It fully explores the Klyntar's noble culture and their mission. Flash and his now-reformed Symbiote travel the galaxy, helping those in need and fighting injustice, embodying the true potential of a perfect Klyntar-host union. This series was critical in solidifying the Klyntar retcon before the subsequent introduction of Knull.
The culmination of Donny Cates' entire Venom saga. Knull, finally free from his cage, arrives at Earth with an army of billions of Symbiote dragons and controlled Celestials, plunging the entire planet into a dome of living abyss. This event was a line-wide crossover that redefined the Symbiotes' place in the Marvel Universe. It revealed their true cosmic origins and power level, forcing the Avengers, X-Men, and every hero on Earth to fight a losing battle against a literal god of darkness. The event ends with Eddie Brock bonding with the Enigma Force to become Captain Universe, defeating Knull, and taking his place as the new King in Black, controller of the Symbiote Hive-Mind.