Spider-Man came in contact with the alien symbiote on the Beyonder's Battle World during the Secret Wars. When his familiar red and blue costume had became torn and tattered from battle he sought to replicate a new costume. He heard from other heroes of a machine that could replicate clothing. Not knowing exactly where the clothing replicator was Spider-Man mistakenly activated a machine that produced a little black ball which slithered over his body when he touched it covering him from head to toe in a black costume.
Returning to Earth, Spider-Man did not give much thought to the properties of his new costume, which could imitate any clothing, dimensionally store small items and had seemingly an inexhaustible supply of webbing. He became suspicious of its properties upon learning it was organic in nature. Taking an earlier offer from Reed Richards (Mr. Fantastic) to study the costume, he discovered that it is a symbiotic organism that was attempting to fuse itself to him both physically and mentally. Richards was able to use sonics to sever the bond and trap the symbiote within an environmental containment cell.
The symbiote would escape Richard's prison and reclaim its host. Disguising itself as the red and blue Spider-Man costume, Peter Parker would not discover it was actually the symbiote until it was too late. He was forced to battle the symbiote while fighting off the Vulturians, a group of convicts that had assumed the technology of the Vulture, wanting to prove their mettle by defeating Spider-Man. After defeating the Vulturians, Spider-Man resolved himself to be free of the symbiote by gambling the ringing bell of a local church tower would drive the symbiote away before he would succumb to the ear shattering noise. The symbiote was driven away, but Parker became unconscious and lay dying. The symbiote, which had been bound to Parker long enough to presumably assume his sense of duty and responsibility, would seemingly sacrifice itself to save its host by dragging him down the bell tower's stairs.
Weak and dying, the symbiote would tune into the emotions of Eddie Brock, a reporter who blamed Spider-Man for his failed marriage and career as a journalist. Brock's series of articles written on the confessions of the murdering vigilante known as the Sin-Eater were exposed to be the ramblings of a compulsive confessor, after Spider-Man captured the actual killer, police officer Stan Carter. Adding further misery to his personal and professional failures Brock was dying of cancer and had gone to the church to beg forgiveness from God for contemplating suicide. The symbiote detecting Brock's strong emotions about Spider-Man bound itself to the new host becoming Venom.
Members:
Typical Symbiote
Current Symbiotes on Earth:
Venom I
Carnage
Toxin
Hybrid
Equipment:
Scout Ships
Former Hosts of the Symbiotes:
Spider-Man
Venom II
Venom III
Agent Venom
She-Venom
Spider-Carnage
Scream
Lasher
Phage
Agony
Riot
