Vampiric Surge (3.5e Feat)
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Vampiric Surge [General Feat]
Prerequisite: Bite attack as a Natural weapons, base attack bonus +4, undead or outsider (evil) type.
Benefit: Once per round, when you deal damage to a creature that is not a undead or a construct with your bite attack, you regain 1 hit point for each size category above tiny.