Augment Elemental

(Magic of Eberron, page 46, DnD 3.5)

[General]

Your knowledge of planar magic allows you to imbue your summoned elementals with extraordinary combat prowess and durability.

Prerequisite

Knowledge (the planes) 2 ranks

Benefit

Each elemental you conjure with a summon spell gains a +2 enhancement bonus on attack rolls and damage rolls, and temporary hit points equal to twice its Hit Dice.