The Clash
Crass
Jello Biafra
GG Allin
Ministry
Billie Joe Armstrong
Andrew Eldritch
Sid Vicious
Seth Putnam
Wait a minute...
Actually, let's just save ourselves some time and say "Every punk or goth musician not named The Ramones, Siouxsie Sioux, or Voltaire"
Other musicians I'd consider to be massive lolcows...
Varg Vikernes
Kanye West
Britney Spears
Madonna
Vanilla Ice
Insane Clown Posse
Taylor Swift
Cledus T. Judd
Sebastian Bach
Axl Rose
Bjork
David Crosby
Then you've got the third category of people who either blur the lines between "massive lolcow" and "brilliant troll" or blur the line between "total sperg and borderline lolcow" and "musical genius"
For the former group, I've already mentioned GG Allin, Seth Putnam, and Andrew Eldritch (though Eldritch seems a lot more self-aware once he got off the speed and the meth) and Negative XP.
(There's a reason why he did that Ramona Flowers song in a punk style, and it was because he knew it'd piss off the Woke Left...)
The latter group of "spergy lolcows that were also musical geniuses" would include guys like Carter Stanley, Jim Morrison, Tim Wilson, John Lennon, and Wolfgang Amadeus Mozart
Musicians who turned out to be horrorcows would include Charles Manson, Bing Crosby, Absurd, some of the Memphis horror rappers from the 90's, Bard Faust, R. Kelly, and Ike Turner.