WARNING: The following contains spoilers for Spider-Man: Spider's Shadow #1 by Chip Zdarsky, Pasqual Ferry, Matt Hollingsworth and VC's Joe Caramagna, on sale now.
The Marvel Multiverse is full of distinct differences and unique figures, with certain decisions proving to be the lynchpins that can result in entirely new realities. One such shift is the result of Spider-Man staying connected to the Venom symbiote and being transformed by the process.
Now, we're taking a closer look at what happened across the Marvel Multiverse in realities where Peter Parker fully bonded with the Venom symbiote.
SPIDER'S SHADOW
Spider-Man: Spider's Shadow #1 explored the fallout of Peter Parker not realizing the symbiote suit was a living organism until it was too late. In this reality, Peter was distracted longer than in the core Marvel Universe, becoming more ruthless in the process. He made things "personal" by unmasking Hobgoblin after their fight, and threatened his life if he continued to cause trouble. When he visited Reed Richards to learn more about the suit, Peter's altered personality and rash behavior prompted him to storm out of the Baxter Building.
However, his control over the suit quickly went out the window. While visiting his Aunt May, Peter discovered that an enraged Hobgoblin had followed him and learned his true identity -- even using the opportunity to attack Peter and May. In the ensuing chaos, May was trapped in a burning building and, due to the weaknesses of the symbiote, Spider-Man was unable to save her. Consumed by rage and transformed by the symbiote into something far more fearsome, Parker murdered Hobgoblin and turned his attention to New York as a whole.
WHAT IF THE ALIEN COSTUME HAD POSSESSED SPIDER-MAN
The reality of 1989's What If? #4 by Danny Fingeroth and Mark Bagley imagined a similar scenario as Spider's Shadow, but with far more tragic repercussions. Instead of visiting Reed, Spider-Man first brings the suit to Curt Conners for analysis. This gives the symbiote longer to fuse with Spider-Man, taking over his body fully. A desperate Fantastic Four tries to contain him long enough to find a way to free Peter from the alien's grasp, but not even Doctor Strange can figure out how to separate the two.
The symbiote only left Peter when it saw a chance to possess a far more powerful being -- the Hulk. Doing so revealed that the symbiote had drained Peter of his life-force, rendering him an old man despite his relative youth. Peter did his best to help the heroes counter the symbiote, but not long after he passed away from old age -- prompting a vengeful Black Cat to sell her services to Kingpin in exchange for helping her gain revenge against the symbiote.
BRAVE NEW WORLD
In 1998, What If #114 by Jay Faerber and Gregg Schiciel introduced a reality where the Marvel heroes who were brought to Battleworld were never able to escape, and instead made new lives for themselves after the original Secret Wars. While many of the heroes and villains had co-mingled and had families, Spider-Man remained alone and bonded to the symbiote, fully fusing with it and finding an equilibrium between himself and the alien life form.
The two became permanently fused over the years, considering themselves a "we" after twenty-five years together. Despite becoming increasingly creepy to the others, Spider-Man remained an ally of the heroes, fighting alongside them against the new generation of the Masters of Evil. In the process, it was revealed that Spider-Man was really only the symbiote, with a sonic blast from Klaw revealing nothing left of Peter beneath the symbiote except for his skeleton. However, the Human Torch was able to save his old friend, admitting that he'd grown tired of the thing that had once been Peter Parker.
VENOMVERSE
The 2017 crossover Venomverse by Cullen Bunn and Iban Coello introduced multiple versions of Venom from across the Marvel multiverse, working with the Earth-616 Eddie Brock to fight back against the encroaching and invasive Poison species. One of the versions of the symbiote that Venom encountered was an incarnation of Peter Parker who had taken the symbiote back from a sociopathic version of Eddie Brock by force.
With no other options for what to do with the symbiote, this Peter Parker re-bonded with Venom -- but retained control over himself in the process. Initially, he and the Earth-616 Venom bristled against one another. But they were able to briefly work well together against the Poison Hive -- until the Hive tricked Spider-Man with a vision of his deceased Aunt May and killed him, adding that version of Spider-Man to the ranks of the Poisons.