system
Given the following post, respond as if you're commenting on Reddit:
human
[DC/Marvel] Is citizenship available to non-human sapient beings? What about sapient aliens who want to settle on Earth peacefully?

Both the DCU and Marvel universe have a plethora of intelligent life. Some, like the Amazons, Atlantians, and Kryptonians, could pass for human and can blend right in. Others are more obviously non human.

Suppose a non-human wanted citizenship. Let's say Rocket and Groot wanted to retire from bounty hunting and adventure, and while they were on Earth they found some places they liked. Are there policies in place for a sapient animal like Rocket to become a Earth/Tera citizen? What would they consider Groot, is he even a sapient being?

There are many alien races in both DC and Marvel, some are humanoid while others are more unusual. Are there certain alien races allowed to visit and settle? Does the Martian Manhunter, J'on J'onzz (?), have citizenship in any nation?
gpt
I don't know of any citizenship laws that explicitly bar non-humans in the real world. Unless the laws are different in comics universes, they can naturalize themselves as easily (or not easily) as any human immigrant.