The players encountered a Hound Archon Hero and his Bronze Dragon mount, straight from the Monster Manual. He guarded the tomb that they wanted to enter. After some friendly chat, they agreed to an all-subdual fight.
That achon did a very good job trouncing the party. The monk refused to fight someone good. Three other characters took dirtbaths. The dragon mount took a dirthbath. The archon was down to the barbarian when he concluded that a loss was invevitable, so he ceded the fight.
I loved subdual challenges. You get to trounce the party without anyone dying.