It's a Kamadan.
See "Iron Gods" from Paizo.
Of course, the problem with WotC revisiting "Barrier Peaks" is right there - Paizo have tackled a similar theme very recently. That doesn't mean they shouldn't do it, of course, but it does mean they should probably make sure to go in a different direction with it.
My thoughts too, plus the Legion of Gold for 4E's version of Gamma World had a strong Barrier Peaks influence.
Then again, Tiamat was the BBEG in 1E, 3.5E, 4E, and 5E so they're prepared to go back to the same creative well....
I am not familiar at all with t...onsters, but my first thought when seeing just the look of 3/4 of them was that the adventure's theme could be invasion from the Far Realm. Which also means, introducing psionics in final version.
Why Barrier Peaks? Only ONE of those four monsters was in the Barrier Peaks... and it wasn't even unique to that adventure!
Barrier Peaks AP?
Correction: A spaceship-full-of-weird-monsters-and-magiclike-technology-crashes-in-the-Realms AP?