Comes from the Chris-Chan troll, orbiter, enabler, white knight, Anthony Logatto who would frequently get angry about Chris and go out of his way to prove how much better he was than Chris.
Now it means anyone who goes overboard obsessive over a cow, where it's obviously no longer fun for them, and their posts reflect how seriously they take everything.
Eg. "OMG can you believe (cow) did (thing)

, look at this lmao lmao lmao they're so fucking stupid, lololol why don't they just kill themselves already GOD what a trainwreck" but times a thousand.