Needs review
Source: Heroes of Horror

Description: Your spells deal extra damage to a particular type of creature.

Prerequisites:

When you cast a spell that deals damage against a specific creature type, you deal an extra 2d6 points of damage. For example, a giant bane lightning bolt cast by an 8th-level caster would deal the usual 8d6 points of damage to any non-giant in its path but would deal 10d6 points of damage against giants. This feat has no effect on spells that do not deal hit point damage, and the source and type of the damage remains the same. This feat cannot be used to increase the amount of healing dealt to undead by inflict light wounds and similar spells, but it can add to the damage dealt by casting cure light wounds on an undead creature.

Special

You can take this feat multiple times. Its effects do not stack. Each time you take the feat, you must apply its effects to a different type of creature: aberrations, animals, constructs, dragons, elementals, fey, giants, humanoids, magical beasts, monstrous humanoids, oozes, outsiders, plants, undead, or vermin. If you choose humanoids, you must select a particular type of humanoid, such as dwarf or orc.