I like the smooth, drapery of wet flesh sort of look. A "proper" shoggoth is foamy looking IMO, but there's no shortage of amorphous monsters it could be great for.
I do have to agree with gary42 about the big topmost mouth looking too square though. It's a combo of the "jaws" being flat-fronted with the way it sticks up in a sharp, right angled way from the mass. Gives it a sort of "air conditioner cover" shape. Needs more curve and slope, like the mouth on the lower left of the mass in the top left pic in your last post.