i dont remember what they were called but there are the monsters that are like daylight zombies mentioned in the comic
when kanaya was talking about rainbow drinkers with rose i believe

i could also imagine a troll horror movie about grubsauce being not fully processed and little grubs clawing their way outside of you?

idk if hemospectrum stuff would be that used in trollian horror, tho i could see that in the way that id think there are two distinct strains of horror on alternia one from highbloods as an actual studio production and one from lowbloods as more of an indie thing
bc iirc karkat had mentioned that troll movies are a high art but ie the thresh prince is more of a looked down on thing (tho it might just have been that its a tv show instead of a movie)

i think cosmic horror still works either way since the horrorterrors are an everpresent threat
the only question is whether the respective empress would allow them to exist

also im not quite sure but i think the apocalypse buff thing was mentioned to eb a "strange pasttime"? so maybe apocalypse stuff is still a thing for horror its just that our specific trolls are v chill about that specific topic