Karr the Darkener

Karr the Darkener

Karr is in the Dread wastes, in the webby, spidery place north of the Forgotten Mire, near the big wall.

Race: Mogu sorceror

Drops: Imbued Jade Fragment, Mozu's Robe

Grinder

 The Imbued Jade Fragment is a companion pet called Grinder, that looks like a jade version of Pebble!

Nalash Verdantis

Nalash Verdantis

 Nalash Verdantis spawns on a small rocky island on the Isle of Stars in the Dread Wastes.

The respawn timer I witnessed was 25 minutes.
Like all Jinyu rares, he has a couple of nasty abilities that you need to watch out for:

Rain Dance: Keep moving till the cast has complete! It's a oneshotter.
Torrent: Interrupt if you can. Else it also kills.

Apart from that, try and keep your health up and you're fine. I did it in Guardian spec with the free pvp gear.

Loot

Drops: Sack of Gems, Hollow Reed, Chestplate of Manifest Dread.
The Hollow Reed is actually a blue water strider pet called Aqua Strider and as of patch 5.03 bind on pick-up:

Aqua Strider