Venom

Nightmare Moon also known as Venom is one of Spider-Man's archenemies. The name has belonged to several different hosts over the years. The Symbiote could be considered "Venom" itself since technically it has no name.

History
After Spider-Man rid himself of the alien Symbiote that infected his life, it found and attached itself to Eddie Brock, a frustrated reporter who had a grudge against Spider-Man for, what he claims, making him lose his job. They became Venom, and as both hated Spider-Man, sought to destroy every aspect of his life. Venom had gained all the powers and knowledge of Spidey, only enhanced, however he seems to be absent of his spider sense.

Eddie Brock
Probably the most famous incarnation of Venom. Eddie's mother died during childbirth, and as a result his father became cold and distant, instilling a thirst in Eddie to impress him. As an adult, he becomes a journalist for the Daily Globe, and enjoys great success until he mistakenly "outs" a compulsive confessor, Emil Gregg, as the serial killer Sin-Eater. Spider-Man debunks Brock's article by capturing the real killer, and Brock is fired from the Daily Globe, diagnosed with cancer, divorced by his wife, and disowned by his father. Reputation destroyed, he is only able to find employment as a two-bit writer for a disreputable tabloid. Blaming Spider-Man for his troubles, he begins to work out obsessively in an attempt to assuage his rage.

Eventually, Eddie cannot take it anymore. Raised a devout Catholic, he goes to his local church to pray for forgiveness for the suicide he is contemplating - unaware that Spider-Man had used the bells in the selfsame church to drive away the Venom symbiote. The symbiote, lying in wait in the rafters for an appropriate host, bonds to Brock, drawn by his obsession with Spider-Man. In the process, Brock learns Spider-Man's true identity, and Brock's overwhelming hatred for Spider-Man turns the already bitter symbiote's love into a twisted obsession.

As Venom, he becomes one of Spider-Man's most formidable foes: stronger, faster, and immune to his Spider-Sense. He wages a campaign of torment against Peter Parker, invading his private life and threatening his loved ones. He is not altogether evil, though: he exhibits moments of compassion, like rescuing a little girl during a pitched battle with Spider-Man. He even ends up in a few Enemy Mine situations with him - generally to combat the symbiote's "child", Carnage, which has bonded with Serial Killer Cletus Kasady. Over time, Venom slowly develops into a hero and declares a truce with Spider-Man, moving to San Francisco for a time and becoming the "Lethal Protector" of a subterranean community of homeless people formed by the 1906 earthquake. Eddie is eventually abducted by the Life Foundation Organization, which forces the Venom symbiote to give birth to five more offspring, Lasher, Phage, Riot, Agony, and Scream, who beg Eddie for help controlling their symbiotes, though he wants nothing to do with them. note Ultimately, Eddie returns to New York and to villainy following his ex-wife's suicide, temporarily joining the Sinister Six before a falling out with Sandman.

Eventually, it is revealed that the symbiote chose Brock as a host not only for his mutual hatred of Spider-Man, but also for the fact that it could "feed" from the excess adrenaline his cancerous body produces, keeping the disease in remission. However, the symbiote no longer wishes to remain bonded to a dying host, especially one that refuses to feed it. Undergoing a Heel-Faith Turn, Brock, disgusted by the symbiote's growing bloodlust, decides to sell it to the highest bidder and donate the proceeds to charity, knowing it will mean the death of him. Unfortunately, the highest bidder turns out to be crime boss Don Fortunato, who gives the symbiote to his son Angelo.

Angelo Fortunato
The "second" Venom: mostly ignored by both readers and canon. Angelo was the timid son of Don Fortunato, a Mob boss who purchased the Venom symbiote from Eddie Brock thinking it would get his son to man up. Despite quickly mastering the symbiote's powers, Fortunato's fight with Spider-Man turned into a Curb-Stomp Battle not in his favour when he murdered an otherwise innocent impostor dressed as Spider-Man. Angelo fled despite the symbiote urging him to keep fighting, causing it to deem him an unworthy host and abandon him in mid-leap to fall to his death.

MacDonald "Mac" Gargan
After ditching Angelo, the symbiote directly approaches Gargan, already an established super villain called the Scorpion, offering him new abilities in exchange for murdering Spider-Man. Gargan eagerly agrees, and becomes the third incarnation of Venom just in time to join Norman Osborn's Sinister Twelve. He was imprisoned and became a member of the government-sponsored vigilantes the Thunderbolts, taking part in the Civil War and helping hold off the Skrull Invasion. Following Osborn being made the head of SHIELD, Gargan was given a drug that reverted the symbiote to the appearance it had when Peter Parker wore it and joined the Dark Avengers, where he gleefully impersonated Spider-Man. In this guise, Mac frequently went AWOL to take a bite out of crime and started a gang war to ruin Mayor Jameson's reputation. When Mac refused to stop and pictures of him eating criminals threatened to go public, Osborn sent Daken and Bullseye to kill Gargan, and when that failed threatened to dispose of Venom himself. After Osborn's botched invasion of Asgard, Gargan was arrested and forcefully separated from the symbiote by the government, who begin researching ways to weaponize it for the American army. Without his armour or the symbiote to stabilize the genetic degeneration caused by the process that gave him his powers, Gargan's health began to deteriorate until he was broken free by Alistair Smythe and outfitted with a new Scorpion suit.

Gargan's stint as Venom was characterized by an increasing dependence on the symbiote and its powers, despite the limitations that resulted - almost like a drug addict. He became increasingly erratic and unstable, driven by the symbiote's bloodlust to commit cannibalism, even to the point of attacking his teammates and disobeying orders to chow down on street thugs.

Flash Thompson
Peter Parker's former friend. Flash enlists in the army during the Iraq War and is grievously wounded in action, losing his legs while saving his comrades. Lauded as a hero for his sacrifice, he is given an offer by the military: he can "rent" the Venom symbiote, which was subdued by drugs, for 48-hour periods (never long enough for the symbiote to establish control) for use in important missions, regaining the use of his legs in the process. Thompson agrees and subsequently becomes the new Venom, marking the character's transition to fully-fledged hero. In addition to the usual plethora of abilities, Thompson is a trained marksman, and uses a variety of firearms in his capacity as a government-sponsored Super Soldier. However, should Flash become angry while wearing the symbiote or surpass his 48 hour time limit, it will assume control of his body.

After the events of Spider-Island, Flash went AWOL to retain the symbiote and hopefully protect his friends and family. This led Captain America to send Red Hulk after him. Flash teamed up with Red Hulk, X-23 and the newest Ghost Rider against Blackheart while they were in Las Vegas and saved the world from Hell on Earth. With those actions in mind, Captain America placed Flash, under the belief that Flash had the symbiote under control, within the Secret Avengers, the black-ops wing of The Avengers. Flash was called in to stop Carnage from conquering the town of Doverton, Colorado, and defeated Cletus Kasady sans symbiote. Following that, he infiltrated the Crime Master's Savage Six and seemingly kills Eddie Brock, the original Venom, who had been forced to become the new Toxin by the Crime Master. After killing or capturing the remaining members of the Sinister Six, who had kidnapped Betty Brant, he teamed up with Kaine, the second Scarlet Spider, to stop Carnage, who had again escaped from prison and was being used to manufacture an army of symbiote super soldiers to conquer the Microverse.

As a member of the Secret Avengers, Flash began dating his teammate Valkyrie and struck up a friendship with Eric O'Grady, the then-current Ant-Man. After the team's reshuffling during Marvel NOW, Flash left the Secret Avengers roster, moved to Philadelphia, and became a member of Red Hulk's Thunderbolts, though he later had a "falling out" with the team. During an encounter with Daimon Hellstrom, Flash was possessed by an ancient demon, which seems to be getting along nicely with the Venom symbiote to the point where Flash is no longer sure which, if either, takes control of his body during his occasional blackouts.

Flash sets up a new life for himself as a vigilante and assistant high-school gym coach, but came into conflict with Eddie Brock, who survived and tracked him down to Philadelphia. Their grudge match was interrupted by the Symbiote Slayers, parasitic biomechanical organisms similar to the symbiotes themselves, and Eddie and Flash arranged a truce to defeat them. Eddie agreed to leave Flash in peace so long as he continued to use the Venom symbiote for good, but Flash's vigilanteism brought him into conflict with Lord Ogre, a crime lord who put a price on his head. The bounty alerted Jack O'Lantern, a former member of Crime Master's Savage Six, to Venom's whereabouts, and Flash was forced to bond a piece of the Venom symbiote to his teenaged neighbour/tutee Andrea Benton to save her life when her family was targeted, turning her into Mania. Flash confronted Daimon Hellstrom, who revealed Memphisto's hell mark and the demon had been excised, and Flash returned to Mania, helping her escape from Crossbones, who was hunting those who bore the hell marks. Wanting answers, Flash confronted the Venom symbiote and it revealed it passed both the hell mark and demon on to Mania in order to protect him and itself from being taken over. Flash and Andi summon Memphisto, who revealed the portion of the symbiote bonded to her was in fact the clone of the symbiote that had once been bonded to Patricia Robertson, and assisted them in defeating Crossbones. However, he refused to remove the hell mark from Andi, revealing that the deal that bestowed Venom with the hell mark had not been made with Flash, but with the supposedly lobotomized symbiote itself.

Flash later returns to New York after hearing rumors of the Crime Master resurfacing. While Agent Venom engages with the Crime Master's minions, the Superior Spider-Man arrives on the scene and assists in defeating them and exposing the Crime Master as an impostor. Flash thanks him for the help, but Spider-Man remarks that he didn't show up to take down the Crime Master's men, but rather Venom, blasting Flash with a wrist-mounted flamethrower. Flash fakes a surrender, takes out Spider-Man's Spiderlings, and escapes, the symbiote badly injured. He later shows up at Peter's house later in the day, interrupting a luncheon with Aunt May, Jay Jameson, and Peter's girlfriend Anna. "Peter" convinces Flash to undergo surgery to give him cybernetic legs and uses the operation as an excuse to remove the symbiote, which promptly escapes containment and reunites with its original host, transforming the Superior Spider-Man into the Superior Venom. Flash tries to coerce the symbiote to return to him - which it attempts to do, having been turned off by "Peter's" new attitude - but SpOck quickly becoming enamoured with the power it gives him and dominates it with his will, forcing it to remain bonded to him. The Superior Venom sets off to test his newfound power and shortly afterwards Flash is informed that the drugs he had been taking to suppress the symbiote had altered his body chemistry to be dependant on it and without it he only has a few hours left to live. With help from the Avengers, Flash succeeds in reclaiming the symbiote from Superior Spider-Man, becoming Agent Venom once again, and returns to Philadelphia.

After amicably leaving the Thunderbolts, Flash is confronted by Tony Stark, who tells him of the Guardians of the Galaxy and feels that there needs to be an Avenger with the team after having spent some time with them. Flash is completely dumbfounded by the descriptions Tony gives him of these heroes, especially Groot and Rocket Raccoon, but decides to accept the offer. Though the Guardians are quick to be dismissive of Flash after seeing his handicapped form, it's quickly tossed aside once they see him as Agent Venom. Before leaving, Tony gives Peter "Star Lord" Quill a device in case the symbiote goes out of control and there's no way to stop him normally.

Otto Octavius
After a brief fight with Agent Venom, during which he discovered that Flash Thompson was behind the symbiote, Flash sought Peter's help in giving him a place to stay. Octavius eventually convinced Flash to allow him to perform a procedure that would give him robotic leg implants, though during the procedure he forcefully removed the symbiote from Flash. The symbiote, feeling isolated and scared, broke out of containment and bonded to Octavius, creating a "Superior Venom".

Despite claiming to be able to exert full control over a reluctant Venom symbiote, Otto became even more erratic than usual: he wounded Cardiac and fleed, hoping to find a villain to physically overpower, proving his newfound might. Failing to do so, he started beating up and scaring petty criminals, until Anna Maria called him to find relief about "Peter" and Aunt May arguing about her. This prompted "Peter" to storm Aunt May's home, loudly berating her for her actions, then directing his anger towards MJ, guilty of having taken May's side. As soon as MJ tried to counter his anger, Otto summoned the Venom symbiote and flees, warning his former family to stay away from him.

After almost killing two robbers, Venom was confronted by the Avengers, who with the aid of Flash Thompson clad in an Iron Man armor managed to defeat Octavius. Flash managed to convince the symbiote to return to him, and as Otto tried to cast him out, Peter Parker's consciousness returned to help him purge the symbiote, but later remained under the radar. Back as Spider-Man, Otto lied to the Avengers and Mary Jane that his behaviour in the past months was due to microscopic fragments of the symbiote slowly multiplying within him. When the Avengers talked to Tony Stark about the test they previously conducted on Spider Man and found nothing, Stark decided to check the data further, and discovered that all of it except the one he knew about had been erased by Spider-Man. With this in mind, Captain America proclaimed that they would need to bring Spider-Man in. After being confronted by the Avengers once more because of the missing medial scans, Otto escaped.