Mad Foam Rager

 
Prerequisite(s): Rage or frenzy ability.
 
Benefit: When fighting, you can endure tremendous blows with little visible effect. As an immediate action, you can choose to delay the effect of a single attack, spell, or ability used against you. The damage or effect does not take hold until the end of your next turn. You can only use this ability while under the effect of your rage or frenzy ability. You can activate it once every time you use your rage or frenzy ability.
 
Source: PHB II