1. Ebon Hold
While in Ebon Hold with your pet you can use its 'Gnaw' ability on a player near any guards. This will cause the guards near you to attack you and any guard there after you go near. I am unsure if they yield any loot or any experience or reputation loss.
2. Leap
Leap has multiple interesting uses:
A. Using 'Leap' on a targeted player will put them into combat. Thus stopping them from mounting or doing anything that requires out of combat. (Does not work in dalaran/shattrath).
B. You can use 'Leap' on many various NPCs in Dalaran. This will cause them to attack your ghoul and you. You will be unable to attack them back; however, you can keep them in combat and kite them anywhere you please. ** Some NPCs cast spells, a prot warrior in your group could spell reflect these and slowly kill them. This works on the Flight Master in Dalaran. A ret pally with retribution aura should work similarly. **