Yes, this pet your looking for is called "Wraith" If you want the pet you MUST to be: A student of the DEATH school. 2# You must be a level 48 to reach this quest. *Note: You can get the PET Wraith and a new Death spell*
I'm amusing you mean the wraith pet and I hate to break it to you, but you have to be death and level 48 and above to be able to use it, well you need a level 48 death character to get it so yeah, sorry.
Yeah awhile ago I thought there was a nightshade pet so I farmed and farmed. So don't feel bad that you thought there was a nightshade pet because I thought there was one too. The actual pet that looks just like nightshade is called Wraith which gets rewarded to death wizards when the turn in their quest to get their lvl 48 spell. Hope this helps!