Is the dark carnival an actual place that purple bloods made or is it just a boggie story to scare wigglers?

If I recall, there was Concept Art of some creepy Carnival on Alternia, and Meenah and (Vriska) visited a memory of something similar once. Even if the Dark Carnival didn’t exist on Alternia, though, it certainly did on Alpha Earth after Violent J and Shaggy 2 Dope became Dual Juggalo Presidents of the United States.