This question already has an answer here:
I just noticed on this post that the Community ♦ user wears the 'Ooh, Shiny!' secret hat on Meta Stack Exchange. This is not the case on other sites, like Stack Overflow and a handful of others I checked.
It probably earned this hat
due to the Roomba script, or when an OP confirmed a duplicate
but why does it wear a hat, and only here?