Anyone seen a Herald of Terror yet?

Graphic-wise, they're completely normal elite monsters with a pack of minions, the only difference is the Herald itself has a purple effect floating above their head. And as far as I've seen they always have an aura (

Concentration,

Thorns,

Vigor...!)

[EDIT] oh I've got a screenshot here of the first one I encountered:

Btw, their name is always "Herald of ..."

Yes, three in a row during separate TZ

Baal runs. All were in the

Throne of Destruction. They were just regular level monsters with swirling purple halos above them.

Nothing good dropped yet.

I saw one just by chance in the recent Cow Tz. In other TZs I'd received the message the Herald Is hunting you (

Frozen Tundra). I looked and cleaned the entire lvl but I saw no Herald, the same happened in the triple Kurast TZ, for

Lower Kurast. Again I cleaned everything and again I saw nothing, and I decided the problem was probably me. So when the "you're being hunted" message popped up during cows, I took my time and went carefully. Moments later I noticed that one of the harder to kill cows now nearly dead had the Herald label. It occurred to me that I was killing them too fast to identify them. So I'll try to not kill them too quickly and maybe I'll be able to get a screenshot.

I did take a screenshot of the message I got in the triple Kurast TZ.