There are brine imps at the Engwithan Digsite, which are untargetable, yet they see a party member in stealth. They do not become hostile or targetable after detecting the party.

Steam, v.1.1.1.0064, all DLC.

 

https://drive.google.com/open?id=1zNV9gVpKAKgEGnLSqVO8J6i8YZBhkDu7

 

Unrelated question: How can I attach files larger, than 1MB, here or post screenshots without uploading them somewhere else first?

Same with a Flame Blight (?) in the Cavern of Xaur Tuk-Tuk. The problem is that I can't recruit Mother Sharp-Rock while the Blight is alive.