It appears to be the Community
I have had one of these edits on one of my answers. It was from Anonymous correcting my misspelling of “Silver”, i wrote both Sliver and Silver in the answer.
I accepted the edit and, as i was the author of the question, it was automatically accepted. I went to check the answer i wrote and it said “Edited by Community”, meaning the Community User.
However, the Community left me a message
In the edit, i had a message that seemed personalised towards my answer. Normally when making an edit to a post, you put in a description of what you have edited, such as “improved formatting” or “corrected spelling”.
The edit description i got was “Silver not sliver ;)”. This seems like a very strange message for a bot to put in. Either someone has had to program the Community User to write that specific message or whoever wrote that was not a bot. Yet the edit still says it was from the Community user when accepted but said it was from Anonymous when it was suggested.