Ok.. I really think this new pet and ability is really cool, and I'm HOPING that there we will be some PVE instances were the ability is useful. I thought having a thread listing where it can be effectively used would be a good idea.
Reflective Armor Plating
30 sec cooldown
Deflects all spells cast in front of the Direhorn for 6 sec.
Note: You have to get the Ancient Tome of Dinomancy and learn the ability to tame Direhorns. These drop off of Zandalari Dinomancer. The drop chance isn't too bad. Didn't take to many kills to get one. Maybe 15 minutes of farming.