Shifter Rage (3.5e Feat)
From D&D Wiki
Shifter Rage [Shifter, Rage]
When you rage your shifter nature takes control.
Benefit: You involuntarily shift when you fall into barbarian rage. You gain both the attribute bonus and the shifter abilities (as far as they are usable during rage). This shifting does not require an action and it does not count against your daily limit of shifting. It ends with the end of your Rage.