I have never seen them. I don't think that's a color way that was released with the four legged frogs either. I don't see any thing that makes them fake in the picture either. Don't know if I'm missing something or of these are real. If they are I really like the color way
Matte White/Black stems came from the Matte White/Gold Iridium Frogz...the Matte Black front could've came from the Matte Black/Violet Frogz and the only non-collab pair that had Black Iridium lenses were the Antifreeze's...so that's probably how they did that pair.
I've also seen them take the Matte White front with the Matte White/Turquoise stems and through in some Blue Iridium lenses from the Fades or Blacklights and call them "Unreleased Four-Legged Frogz".