I don’t remember seeing it with my necro, but on my squirrel build (ie. wolves), I noticed that one of the little furries runs off in random directions and attacks things (but none of the others do…) - I’ve concluded that he caught rabies and has become rabid…
In all seriousness; it’s not neccesarily a bug per se, but if one does it - they should all do it…
I was catching up to a friend when one of them shot off; he started laughing and said “yup, there he goes again…” and i saw on the mini-map that one of my pets was just at the edge of the screen all by himself. This happened the entire night.
Again, not a bug - but it would be nice if they were uniform…
Thanks 
(and give thanks to whoever created the Herald of the Scurry - it is by far the best item ever created…)