You use substitute verbal and somatic components when casting spells.
Prerequisites: Wis 13, nonhumanoid ог nonhumanlike form.
Benefit: You complete the verbal and somatic components of spells by substituting vocalizations and gestures appropriate to your shape. You must still have suitable appendages and vocal organs. For example, a giant eagle could substitute screeches and waves of its talons for the normal verbal and somatic components of a spell. You can use any material component or focus that you can hold. This feat does not permit the use of magic items by а сгеаture whose form could not ordinarily use them, and you dо not gain the ability to speak if you cannot already.
Source: Savage Species, page 39.