There's a bug that causes the spawn of The Lamb and Breaking News (the Nuggets and little Breaking News) to be impossible to kill in that, when you drain their health to 0 (which should normally kill them), the stop taking damage and become completely invincible. An error appears in the console when this happens. Anyone else encounter this?

Edit: It'll actually happen with all enemies. I don't know why, but it'll at least happen when they kill each other.