I am really looking forward to any behind-the-scenes they do on the effects work on this. I’ve heard Kuiil referenced as being motion-captured, but that sure looks like a physical costume. And the Yadpole is so, so likelike. It’s amazing.
I believe I read that Kuiil was portrayed on set by a small woman wearing an animatronic mask which was controlled via facial motion capture on Nick Nolte. Just going off some random article though, no solid proof on that.