The unnameable was improbable on film as the monster should have been considered indescribable as well.
Agreed. That’s a point I’ll address in a little more depth when I get to that story. It’s well suited for adaptation into a short, but it’s a poor choice for a feature; the original story really only occupies the first few minutes of the movie. From Beyond faced a similar difficulty, and the entirety of the source material for that one is basically covered in the film’s pre-credits sequence, but there the combination of a more versative central concept and more inventive screenwriting justified the expansion a lot better.