"I'm very large with shadows, y'know.. I can slip in an' out of 'em like wind through a fence."
Anybody's (Susan Oakes) is a minor character in West Side Story. Her character is loosely based on Balthasar in Shakespeare's Romeo & Juliet; Balthasar was a servant and informant for Romeo.
Anybody's is a tomboy and often tags along with the Jets even though most of them, especially A-Rab and Baby John, don't like her much. She fancies herself to be tough and scrappy and, like Action, is quick to fight with anyone who insults her, but despite her repeated pleas to be made a member of the Jets, Riff always refused and sent her away because of the mere fact that she was a girl.
After Riff is killed at the rumble, Anybody's takes it upon herself to go undercover for the Jets, hiding in the shadows and infiltrating Sharks territory. When she tells Ice about how she learned of Chino's intention to shoot and kill Tony, they all split up and search for him. When she asks what she can do to help, Ice advises her to go back into the shadows in the hope that she'll find Tony in one of them. Ice officially makes her a Jet when he tells her "Ya done good, Buddy boy", to which she replies "Thanks, Daddy-O".