system
Given the following post, respond as if you're commenting on Reddit:
human
[DC/Marvel] who would be a good marvel villain to add to Batman's rogues gallery?
gpt
Any of Spider-Man's villains would fit pretty seamlessly into Batman's world, with the exception of the symbiotes.  

Specifically:

Green Goblin - brilliant scientist and CEO of a major company driven mad, perfect Bat-fodder.

The Chameleon - master of disguise versus master detective? Nice!

The Rhino - dumb Bane/human Killer Croc

Doc Ock - genius scientist with a human body and cybernetic attachments?  Good match for the Bat.

Mysterio - powerless master of illusions keeping Batman on his toes? Works for me.