https://e621.net/posts?tags=otter+space+lost_my_keys This infamous post makes me wonder what connection between those artist tags is. Is it just a mistake because it's supposed to be the character name?

it's the same person. Aliases combine x tag to another because having multiple tags for the same thing is pointless

alphamule said:
https://e621.net/posts?tags=otter+space+lost_my_keys This infamous post makes me wonder what connection between those artist tags is. Is it just a mistake because it's supposed to be the character name?

You can check whether artists have multiple aliases by going into their artist wiki; e.g., zaush.
Some artists also do keep their SFW/NSFW aliases separate though for personal reasons, but you should be able to find mentions of it on their respective wikis.

Ah, oops. Did search for adam_wan and got results on some IRC bot. Didn't realize it was already aliased. Sorry. If I had just clicked on the Wiki...