"From the steamy recesses of the southern swamps comes a figure cloaked in mystery. The Necromancer, as his name implies, is an unseemly form of sorcerer whose spells deal with the raising of the dead and the summoning and control of various creatures for his purposes. Though his goals are often aligned with those of the forces of Light, some do not think that these ends can justify his foul means. Long hours of study in dank mausolea have made his skin pale and corpselike, his figure, skeletal. Most people shun him for his peculiar looks and ways, but none doubt the power of the Necromancer, for it is the stuff of nightmares." - Blizzard.com
The Necromancer has 3 separate skill trees:
Summoning | Poison & Bone | Curses |