Got attacked by an Elder Grievewraith in Skinner's Roam outside of the gates of some Infested Ruins.

The battle was brutal (highly recommend going there for the thrill) but I haven't been able to find another one ever since. I want to tame one but haven't been able to find another.

Also, I found the Elder one outside of the gates (more like it found me lol) so I was expecting to find another one inside of the ruins but I had no luck.