Re-reading Lord of the Rings, albeit, far more closely this time. This passage struck me as describing DUmmies well. It happens in Return of the King after Frodo and Sam witness one orc killing another out of annoyance and for no other reason:
"But that is the spirit of Mordor, Sam; and it has spread to every corner of it. Orcs have always behaved like that, or so the tales say, when they are on their own. But you can't get much hope out of it. They hate us far more, altogether and all the time. If those two had seen us, they would have dropped all their quarrel until we were dead."