1.2mil exp/hour 90-92 [Rested]

I was leveling my 91 rogue when I came across the quest Shadows Awaken - Quest - World of Warcraft


The quest objective is to kill Karnoth - NPC - World of Warcraft and I noticed he gave 15k exp (Rested)
So I threw down a Guild Battle Standard - Spell - World of Warcraft and chugged a Excess Potion of Accelerated Learning - Item - World of Warcraft which bumped it up to 20250 per kill!



When you accept the quest it takes 30sec for the mob to spawn and another 30 to kill him (depending on gear)

Then you abandon the quest and retake it.
20250*60=1215000exp/hour


Horde has the equivalent quest The Butcher of Bladespire - Quest - World of Warcraft which I assume works the same way. (Don't have a 90 horde)