Early reports from the PTR claim that the frogs that hang out around the altar/forested area early in the instance are actually humanoids cursed by Forest Troll voodoo. Players can use Amani Hex Sticks looted from Zul'Aman trash mobs to transform the frogs back to people.
Those un-cursed people leave behind money, Amani Charms or sometimes transform into vendors. For sale on these NPCs is various items, possibly including stat food, a new non-combat pet, Mojo and/or a Sealed Scroll Case that contains a random profession recipe scroll. The scroll can even be for an epic recipe.
The new non-combat pet, Mojo, is a blue frog companion with a special talent. If you /kiss Mojo, he will turn you into a frog and whisper sweet nothings into your chat box. Which is why I've always been against PDA (public displays of affection.)
Finally, on your way out of the zone, all the transformed humans will cheer you on your way out. And then, presumably get hexxed back into frogs for the next round of adventurers.