It chatters incessantly like a Yesman and it mills around in the same pattern. The only difference is, I killed it already.
I don't think it was recently promoted. There was a group of four Yesmen and four Pit Bosses. I killed the Yesmen first, then the Pit Bosses were all demoted and I killed them. After that, I noticed the Yesghost. Trying to hit it does nothing.
