Horrorcow is an old school term for any lolcow that has done horrible things to people but still spergy enough to rage at trolling. Tommy Tooter is the best example of this because he's notorious for threatening litigation and trying to get the phonebook of everybody that makes fun of him, even though he masturbated a female dog, sexually assaulted a teenager, drove a woman who had a terminal illness to kill herself, and always getting himself wrapped up in "Get Rich Quick" schemes. In conclusion, the tag exists because some Lolcows are genuinely fucked in the head but still reacts to trolling very harshly.