Sleeper's History
The seventh spawn of the Venom symbiote, Sleeper was the result of an unusual and difficult pregnancy. Delivered by Doctor Steven at Alchemax's astrobiology laboratory, the infant symbiote narrowly avoided being captured by the Symbiote Task Force and bonded to the Scorpion. Worried that bonding to a host at such a young age would corrupt it into a monster like its siblings, the Venom symbiote and Eddie Brock opted to leave it in the care of Alchemax; stipulating that it could only be studied in a non-invasive fashion.
As Sleeper matured and began developing unique chemokinetic abilities, Alchemax CEO Liz Allan proposed harvesting its secretions to turn a profit, though Eddie and Venom refused the offer and threatened to take action against Alchemax if Liz did so. When the Venom symbiote refused to return to its original host, the Kree soldier Tel-Kar, he took the Sleeper symbiote hostage and threatened to bond with and corrupt it unless it complied.[6] Angered by the loss of its parent, the Sleeper symbiote used its pheromone manipulation abilities to interject into Eddie's thoughts and proposed bonding to him in order to save Venom. While Eddie was initially reluctant to do so, Sleeper broke free of its container and bonded to him, accompanying the Skrull Warbride M'lanz into space to track down Tel-Kar.
Insulted by M'lanz questioning its abilities, Sleeper knocked her out and - upon observing Tel-Kar had unleashed the bio-weapon on the Skrull space station it was contained within; set out without her. Tel-Kar attempted to immolate Sleeper, but the symbiote used its superior invisibility to catch him off-guard. Incapacitated, the Sleeper symbiote interfaced with its progenitor, who broke free of Tel-Kar's control. When Tel-Kar punctured M'lanz's hazmat suit to expose her to the bio-weapon, the Sleeper symbiote left Eddie to plug the hole. Temporarily bonding to M'lanz, the Sleeper symbiote returned to Earth while the Kree armada arrived and destroyed the facility. When Tel-Kar escaped and tried to kill Eddie and the Venom symbiote, the Sleeper symbiote bonded to and lobotomized him as revenge for what he had done to the Venom symbiote. Despite Eddie being dismayed by this, Sleeper bid him farewell and set out to explore the cosmos, using Tel-Kar's mindless body as a puppet host.
Eventually being drawn to Klyntar and learning of the existence of Knull, who tried to assimilate Sleeper into his dark hive-mind. Escaping, Sleeper realized that Eddie was in danger and returned to Earth as quickly as he could. Arriving on Earth, Sleeper protected Eddie's son Dylan and Normie Osborn from the Phage symbiote -- who alonside its siblings Riot, Agony, and Lasher had been corrupted by Knull and were serving Carnage; who had bonded to the primordial Grendel symbiote and was seeking to free Knull. It tried to transfer to Dylan, but was subdued and captured by the Maker, who decided to kill it alongside is siblings despite Dylan's protests. When Dylan unleashed the Life Foundation symbiotes in an attempt to stop him, Sleeper was left trapped and powerless to help as the Life Foundation symbiotes merged into Hybrid and took over the Maker.
Upon the arrival of Captain America, Thing, Wolverine, Spider-Man, and Bruce Banner, Dylan freed Sleeper from containment. The symbiote attempted to bond to him, but was repelled by Dylan's symbiote powers. Dylan forcibly seized control of Sleeper and shaped it into a wolf, siccing it on Hybrid. Controlled by Dylan, Sleeper doused Hybrid in napalm, which was set ablaze by Hawkeye. After the battle Sleeper berated Dylan for forcing it to do things against its will, but was called out on its hypocrisy for having done so to Tel-Kar. Reconciling, Sleeper asked why Dylan had chosen the form of a wolf before shaping itself into the form of a cat. After Carnage and his forces ambushed the heroes at the warehouse, Sleeper, along with the other heroes, fought them, while Eddie who had bonded to a symbiote formed from the extracted codices, fought Carnage. Afterwards, Sleeper in its cat form, begun living with Eddie and Dylan in Liz's home.
After Eddie went to Isla de Huesos to keep Carnage away from his loved ones, Dylan began succumbing to the influence of Knull, and used his powers to hide from Sleeper the piece of the Carnage offshoot that he got. When an enraged Dylan lunged at Normie during an argument, they went through the window, causing Sleeper to go save them and discover Dylan's secret. He wanted to absorb the piece in order to keep the children safe, but Dylan convinced Sleeper to let him to keep the symbiote piece and promised to tell Eddie.
Sleeper then assisted Dylan in using his powers on the Carnage offshoot in order to better understand them and find a way to defeat Knull, as Dylan began to unintentionally inflict pain on the offshoot, Sleeper also felt the pain until he turned it into a portal. Dylan went on to possess the Venom symbiote during the fight between Eddie and Carnage and was eventually thrown out of the portal where Sleeper caught him, but began burning from Dylan's influence before he ripped the offshoot off him.
After Knull's defeat, Sleeper went to live with Eddie and Dylan in a house that Tony Stark bought in appreciation for saving the world.
