Warning: contains major spoilers for Spider-Ham: Great Power, No Responsibility!
Accessing the Spider-Verse in Marvel Comics has become easier than ever. While the connection between the worlds of the many different spider-themed heroes has been explored in comics, Spider-Ham has found the easiest methodology for meeting with his fellow variants. He holds the key to the multiverse - literally.
The Spider-Verse is part of Marvel's broader multiverse. It includes every alternate iteration of Spider-Man across various dimensions. It was the focus of the animated feature film, Spider-Man: Into the Spider-Verse (2018), which included Spider-Ham - the hero of a newly released graphic novel.
Spider-Ham: Great Power, No Responsibility, comes from the creative team of Steve Foxe, Shadia Amin, and Rae Crawford. In the story, the titular Spider-Man variant is awarded the key to the city, which he promptly loses and has to find. During his search for that key, he talks to a variant of Doctor Strange - Croctor Strange - who has a trunk full of different keys. While searching for the one he needs, Spider-Ham picks up one with a spider-web handle that seems rather promising to him. This key reveals a magical floating lock, that, when unlocked, seemingly goes straight to Earth-616 and the original Spider-Man.
This doorway being opened makes Peter Parker wonder if trouble is brewing. After all, typically crossovers only happen when there's a major threat. In this case, however, the only danger is Spider-Ham and his lack of responsibility. A heartfelt talk leads Peter Parker to teach Peter Porker about the importance of responsibility, which would be a good lesson if Spider-Ham could act accordingly. He selfishly puts himself ahead of everyone, in this story by webbing the monster that Croctor Strange is fighting and throwing it into Peter Parker's dimension before walking away - closing the dimensional doorway.
This is a pretty significant revelation as it's clear the Spider-Verse is easily accessible using magic keys, without even having to be a Sorcerer Supreme. A key user just has to walk through the door. This is definitely one of the easiest ways of accessing another dimension, particularly for characters who aren't capable of casually opening up dimensional portals. Were there actual threats, it would be easy to gain access to allies, gather information, and rally against foes.
Unfortunately, this usefulness may never come to fruition since it is information known by Spider-Ham - one of the most unintentionally selfish and negligent heroes in Marvel's comic universe. If Spider-Man could get hold of a similar key from Earth-616's Doctor Strange, it could still be possible to have quick access to the Spider-Verse and his allies within it. If not, the fate of the world could be entirely in Spider-Ham's hands - a rather disturbing thought since this Spider-Man variant still has a lot to learn about being a hero.