Aspect of the Chameleon

More commonly known as Aspect of Paranoia.

In Legion this item is sold by Lucas Sigmund at Nesingwary in Highmountain for 50 gold.

While Aspect of the Beast/Chameleon was very useful in World PvP situations where it allowed you to stalk Hunters and Druids without them knowing, especially hunters who rely heavily on their minimap to be aware of the presence of enemy players (they are blind otherwise if you are out of their line of sight).

Unfortunately, I got this tome in Legion and it appears Blizzard ruined it. Where as before this spell was a permanent spell which you could toggle on or off, it only last 1 minute and has a 3 minute cooldown.. essentially making it completely useless, as sometimes you can stalk an enemy hunter/feral for minutes at a time, just waiting for the perfect opportunity to catch them off guard, usually when they dismount off a mount or are alone.

Druids track Humanoids too. And it was hardly useless. On active PvP servers this really came in handy especially in certain zones. Not to mention Battlegrounds. And the Melee AP wasn't useless either. It was essentially a 'nerf hunter, buff pet' effect. You'd have understood all this if you played Hunter extensively during WoTLK and especially if you were an active PvP'er. Now we have Camouflage to help with not being tracked, so I guess that's the main reason why they removed it.