Scramble

(Savage Species, page 39, DnD 3.0)

[General]

Your slippery ways allow you to evade a damaging blow.

Prerequisite

DEX 15, Small size or smaller, improved evasion

Benefit

The effects of this feat resemble those of the rogue's defensive roll, but you can use Scramble to avoid a potentially fatal attack entirely. Once per day, when you would be reduced to 0 hit points or less by damage in combat (from a weapon or other blow, not a spell or special ability), you can attempt to scramble out of the way. This requires a Reflex saving throw (DC 10 + damage dealt). If the save is successful, you avoid the damage entirely. You must be aware of the attack and able to react to it; you cannot use Scramble if you are denied your Dexterity bonus to Armor Class.

Special

Since you cannot normally make a saving throw to avoid the damage from a blow, improved evasion does not apply. That is, you cannot save twice against the same attack.