Energy Absorption (3.5e Creature Ability)

Energy Absorption
Summary::You aren't just immune to an element, but are healed by it.

Some creatures absorb energy damage instead of being harmed or being immune to it, often by virtue of being composed of the component energy. Creatures which are struck by an energy type they absorb are not damaged, but instead healed by an amount equal to the damage normally taken. Creatures which are struck by a beneficial energy typically choose to automatically fail their saves against damage for maximum effect.

Energy absorption is more powerful than energy immunity; an ability that can defeat immunity (including anti-resistance) cannot defeat absorption unless the ability says that it can or (for SRD and other official sources) is listed here as being able to defeat absorption.

Some creatures derive a benefit other than healing from their energy absorption; this will be noted in the creature's profile.