Venom is a recurring character in Marvel's Spider-Man series. It is a symbiote who bonded with a host’s body.
It briefly appears in both endings of the first game (post-credits) and Miles Morales (mid-credits), where its first host reveals to be Harry Osborn. It will have a major role in the second game/third installment as one of its major antagonists.
Sometime after Harry Osborn's needed treatment, a black substance, presumed to be Venom, clings to his body inside a stasis until a cure for Harry's condition is found.
When Norman Osborn places his hand on the tank in despair, he does not notice that the substance has reacted to Norman's movement.
Marvel's Spider-Man: Miles Morales
While a black substance which is presumably Venom still attach to Harry in after the end of the game, off-screen, Curt Connors is enlisted by Norman to examines and studies the young Osborn's disease, and the substance which kept him alive. Just as Harry wakes up hearing the news of Rio Morales becoming New York City Council since the fall of Roxxon and Underground, Norman becomes impatient of seeing his son remains in the container long enough, and orders Curt to get him out, despite the doctor's warning.
Marvel's Spider-Man 2
Venom is a black shape-shifting substance when not hosting a body. However, when it does, Venom develops a more 'human-like' posture, maintaining a mouth, receiving limbs, and showing it's white, wide eyes.
Powers and abilities
Venom appears as a substance that possesses the ability to host the bodies of other living creatures.
The Symbiote first appeared as Spider-Man's alien costume in The Amazing Spider-Man #252 in May of 1984, with the circumstances behind the costume change revealed in the December, 1984 issue of Marvel Super Heroes Secret Wars.
It would later appear as Venom in The Amazing Spider-Man #299 in April of 1988.