an angered spirit  

The respawn timer on Teek appears to be approximately 3.5 hours with some variance. He does spawn on server reset and pick up, so that's a good way to get him.

The angered spirit is in the westernmost room of the ruins on the northish end next to the cliff (bottom). I pulled it from the west and then north a little ways and never even saw another mob wander by close. Didn't bother to fear kite since he was undead, I just slowed and dotted. Even with slow he beat up both pets to about 40% health. It did not cast any spells. I did this twice, of course, same tactic, same result.