Shanda the Spinner

Shanda the Spinner is a level 18 rare grey tarantula that can be found in southern Loch Modan southwest of Ironbrand's Excavation Site. She spawns in the cave that I have circled on the map below, she does not patrol once she spawns there. 

She drops the typical green item and a fairly decent amount of experience for leveling characters.

She would also make a nice hunter pet for low level alliance characters that stumble across her. She does not have a unique skin or coloration but she is probably the first in this color that dwarven hunters can find without looking too hard. Low level Horde characters looking for this same skin and color should check out Creepthess, another rare spider in Hillsbrad Foothills.

Shanda is one of 5 rare tamable hunter pets in this zone. All of them are:

Ashtail, level 16 bluish-grey fox

Gosh-Haldir, level 15 green crocolisk

Lord Condar, level 17 white condor

Nix, level 17 yellow firefly

Shanda the Spinner, level 18 grey tarantula

Shandra can be found with NPCScan, but it isn't really necessary as she doesn't move from the location that she spawns at. If you do choose to add it, her NPCScan ID is 14266.

Before the Cataclysm her spawn timer was somewhere between 4-6 hours. I believe it has since been significantly reduced.