Like other characters in Marvel's catalogue, Spider-Man has crossed over with Batman and other DC Comics characters. Alongside the Dark Knight, he has helped fight against team-ups between the Rogues Gallery (namely the Joker and Ra's al Ghul) and his own villains, including the Kingpin and Carnage.
Involvement with Batman
Peter would eventually get his love life straightened out. He and Mary Jane got married and moved into a brownstone home. Mary Jane learned of Peter's life as Spider-Man and was supportive of his vigilante activities.
As Spider-Man, Peter was called by Dr. Ashley Kafka to oversee an operation at Ravencroft Institute. The operation, run by Cassandra Briar, would insert a bio-technic computer chip into Carnage's body to control and pacify him. Both Parker and Kafka considered this immoral, but they were overridden as Briar was appointed by the United States Congress. The procedure seemed to work, as the chip not only calmed Kasady's aggression, but also subjugated the symbiote into a state of dormancy.
Briar then went to Gotham City, taking Kasady and Kafa with her as proof the procedure was a success. She then used it on local crimianl The Joker; however, the procedure didn't actually work on the symbiote. It freed Kasady and together they took Joker and Briar hostage. Batman, the city's protector, and Spider-Man, who had secretly followed them, appeared and rescued Briar, but Carnage still managed to escape with Joker. Batman told Spider-Man to stop 'helping' and leave the city. Spider-Man protested to him that he only wanted to help, but Batman stated again that he didn't need or want his help.
As he swung across the city, Peter stopped and a mugger and decided to locate Carnage despite Batman's orders. Suddenly, he greeted by Batman in the Batmobile, who beckoned him to come with him. Traveling in the Batmobile, Batman apologized to Spider-Man for denying his help and that having a friend who knew about Carnage may prove helpful in arresting the symbiote. The two managed to track Carnage's location through a remnant of his chip by tracking its frequency, and discovered their ruined base. The two discovered the body of Carnage but it proved to be a trap, as Carnage grabbed hold of Batman, who told Carnage he'd rather die than submit.
As Carnage is poised to make the killing blow on Batman, the Joker interrupted and told Carnage to back off from killing Batman, as he was the only one who had the right to kill "his" Batman. Joker then revealed a Joker-in-the-Box containing the deadly virus, announcing his plans to unleash it immediately. Spider-Man expressed shock at Joker's mindless disregard for human life, while Carnage displayed abject fear of being killed, giving Batman the edge in combat with the cowardly villain. Spider-Man then snatched the Joker-in-the-Box from the Joker with his Web-Shooters, as Batman subdued a "weak-minded" Carnage into submission, forcing him to revert back to Kasady. Spider-Man traced down Joker and grabbed hold of him, threatening to kill him, which delighted Joker, who was eager at the chance at driving a "goody two shoes" into cold-blooded murder. Spider-Man relented, released Joker, and took him down with a punch, knocking him into unconsciousness.
With the defeat of both Carnage and the Joker, both Batman and Spider-Man thanked each other, wordlessly with a handshake. Spider-Man swung off, returning to New York, as Batman watches over Gotham.
New Age Dawning
While on patrol, Spider-Man stopped a deal involving Kingpin's Henchmen. Finding mysterious markings on the other party's hands, he decided to investigate Fisk Towers. He found Batman also investigating the Kingpin and after agreeing to team-up, he revealed to Spidey that the other party was a terrorist group called the League of Assassins, who planned to destroy Manhattan. Later, they were called by the Kingpin, who gave them schematics to the league's base and computers in retaliation for hurting his wife. Disguised as a pair of his henchmen, Spider-Man and Batman accompanied the Kingpin to Nanda Parbat. Once they got to their laboratories, Spider-Man distracted the league while Batman reprogrammed their computers. Fisk punched in the code to activate their satellite, causing it to self-destruct. After revealing his deception, their leader, Ra's al Ghul, was so impressed he allowed them to leave unharmed.
- Spider-Man has crossed over multiple times into the DC Universe, first doing so in Superman vs The Amazing Spider-Man. He also appeared in the Marvel vs. DC comic event and JLA/Avengers storyline.
- In the Amalgam Universe, Spider-Man was merged with Superboy and Pete Ross, becoming Spider-Boy.