Like, those who are milked for laughs, but also constantly are like “Oh no, what did they do now”? without reaching the cosmic horror levels of a horror cow, even if they have done fucked up shit.
For example: Onision, iiluminaughthii, Dalas Review.
Lolcow refers to an internet personality who trolls “milk” (hence the -cow suffix) for laughs (or “lols”). If you know who Chris Chan is, he’s pretty much the poster child and is where the term came from. Never heard of the term horror cow but I’m using context clues to assume it’s like a lolcow who goes too far in retaliation when they get trolled.
For OP, these are both very specific terms that are used in niche communities in closed-off subgroups. I don’t think there’s a single word or phrase to describe what you’re looking for.
I think a horror cow is someone, often a lolcow, whose life becomes more horrifying than funny to watch. Like finding out about Chris Chan and his mom. Or watching in real time as KingCobraJFS’s body and mind succumb to his alcoholism, nicotine addiction, exposure to unventilated spray paint, and consumption of horrifying foodstuffs.