get one's claws out

Verb

 * 1)  To prepare to attack or retaliate
 * That cat will always get its claws out when it sees a mouse.
 * 1)  To prepare to attack or retaliate
 * You'd better watch out: she's got her claws out for you.

Usage notes
When said of a person, the phrase is usually applied to a woman and the attack is typically verbal or indirect, such as a harming someone socially.