Bone spider

Bone spiders are a unique type of spider that appear completely made up of bone. They can only be found in Northrend in the zones of Icecrown, Zul'Drak, Azjol-Nerub, and Ahn'kahet: The Old Kingdom.

Speculation
These creatures are possibly related to the nerubians who are part of the Scourge. They may be the bane spiders referenced in the Manual of Monsters,
 * Nerubian relations

The name "bone spider" is taken from the game files, as no other name is known.
 * Name