Big Voodoo Pants are made by Leatherworkers and give a bonus to intellect and spirit.
Big Voodoo Pants are crafted by Leatherworkers with a skill level of 240.
The pattern drops off creatures in Zul'Farrak, Maraudon, Blackrock Depths, and The Temple of Atal'Hakkar.
Although not an actual set, there are several other Big Voodoo items:
Big Voodoo Mask, Big Voodoo Cloak, and Big Voodoo Robe.