Enervating Touch (3.5e Feat)
From D&D Wiki
 Enervating Touch [Undead]
Your undead nature allows you to drain the life out of living victims.
Benefit: Your unarmed attacks and natural weapons inflict one negative level. The DC to remove that negative level is Charisma based. You gain 5 temporary hit points every time you inflict a negative level on an intelligent creature in this way.