The guys over at the forums who don't bother making an account. They'll usually have generic names like Kyle, Jimmy, Bob, and Jeremaihah Felschlikt. Other times they'll just be more RPers. They may have twitch accounts or may be just stream lurkers.
Hell this ain't relevant anymore, the forums are barely even a thing because no one uses it, and if there are forum anons, they're not gonna look like the above image
They're gonna look like the bottom one
Behold: Your new avatar