Giant Bone Spider
Drops from Maexxna. Found in a dusty egg clutch at the back of Maexxna's lair, these creatures are already undead when they hatch. Undead type. As of patch 5.1, Maexxna has a decent chance of dropping this pet in both the 10 and 25-man modes of Naxxramas.
The Giant Bone Spider is an undead battle pet obtained from the 
Dusty Clutch of Eggs, dropped by Maexxna in Naxxramas.
Guide awaiting review
Enter Naxxramas Raid
Travel to Naxxramas and make your way to Maexxna's lair. Maexxna has a decent drop chance for the Dusty Clutch of Eggs in both 10-man and 25-man difficulties, so you can run both versions each week for additional chances.
Defeat Maexxna
Defeat Maexxna at max level and loot her — she drops the Dusty Clutch of Eggs, which contains the Giant Bone Spider pet, described as hatching from a dusty egg clutch found at the back of her lair.
Learn or Sell Pet
Right-click the Dusty Clutch of Eggs to add the Giant Bone Spider to your pet collection. If you already own it, the item may be tradeable on the Auction House.
Tips
The Giant Bone Spider is notable as the first and only undead battle pet using a spider model, and its Sticky Web and Leech Life combination makes it a strong pick for pet battles.
Both the 10-man and 25-man versions of Naxxramas share a lockout separately, giving you two attempts per week at the Dusty Clutch of Eggs from Maexxna.
