Goblin Necromancer

Strengths

• The Goblin pop growth bonus is a huge boon to the Necromancer's growth stunted necropoli.
• Stacking Lifesteal with Goblin Butchers and Vampiric Hunger
• Easy access to Weakening gives necromancers a valuable tool against blight immune units
• Extreme blight damage from spells and racial class units
• Cheaper reanimators
• Embalming provides goblins with a much needed hitpoint bonus

Weaknesses

• Very reliant on blight damage
• Fragile units can be a challenge for the low-economy necromancer, especially early game

Specializations

• Shadowborn (stacking lifesteal, even cheaper units, additional damage channel) 
• Water (rot for machines)