Choose one of the creature’s special attacks. This attack becomes more potent than normal.
Prerequisite: Special attack.
Benefit: Add +2 to the DC for all saving throws against the special attack on which the creature focuses.
Special: A creature can gain this feat multiple times. Its effects do not stack. Each time the creature takes the feat, it applies to a different special attack.
Source: Monster Manual (version 3.5), page 303.