Not “fans.” People. Specifically, horror casuals who don’t plan their entire year around HHN. A strong IP is one that entices a person with no interest in HHN to attend. TWD, AHS, Stranger Things, Ghostbusters, and the Big Three (Freddy, Jason, and Leatherface) did that. Conjuring, IT (Stephen King in general, actually) would do that. Billie Eilish, in any capacity, could do that.
Beetlejuice and Gremlins will attract some niche fans, but it’s a niche that’s already inclined towards attending (assuming they hear about it). Your big IPs aren’t niche.
How much Invader Zim stuff did you have to dig through to find it? Hot Topic doesn’t sell horror. They sell irony. You get your horror stuff from there because they’re the only ones selling it.