I disagree that the first one is ungrammatical, although it is rare.
We have some adjectives that are almost always postpositive - 'arms akimbo, evil incarnate, buildings ablaze, prizes galore"
We also see it with titles of works - Mission Impossible, Chicken Little, Body Electric, Paradise Lost.
We also see it in poetic use or for an archaic effect - words unspoken, things forgotten, fiddlers three, forest primeval, creatures unseen, parts unknown, times past
Pronouns tend to take it postpositively as well - nothing useful, something fancy, those responsible.
So while it's rare, it isn't strictly ungrammatical. There's also really no good reason to use it, aside from deliberately wanting to sound overly poetic. It's certainly not something learners want to emulate in normal speaking and writing.
I thought this was going to be a question about a poem when I saw the thread title.