From: Kaze_Memaryu | #006 Most of those look more like Dark/Ghost types.
Just because something looks scary does not automatically put it in the ghost/dark category. ALL of these have physical corporeal forms. I could see Dark/Poison though, but honestly the scary thing about eldritch abominations is that they're not inherently evil but operate on a moral system incomprehensible to our own so pure poison would make more sense. These creatures aren't poisonous to the body but to the mind as they tend to drive onlookers insane. This could also make for a pretty cool ability Pokemon-wise.