Precision Transformation (3.5e Feat)
From D&D Wiki
Precision Transformation [Monstrous]
Years of intense training and practice have left you with minute control over your alternate forms. Gain precise control over alternate form transformations.
Prerequisite: Alternate Form ability, Alternate Form Synergy
Benefit: Making minor alterations to alternate form while transformed does not count as one "usage" of Alternate Form Ability.
Special: Adds +10 to Disguise Checks when attempting to transform into a specific individual.