(idiomatic, mostly used conditionally) in someone's situation.

Fully available to help or to be of use to someone, or some organisation. / (formal) By way of introduction on first meeting another person.

(idiomatic, informal) To save someone's life. / To prevent an undesirable occurrence.

(idiomatic) To rescue (or save) someone from further harm.

(idiomatic) To save someone from embarrassment.

(informal, idiomatic) To take advantage of someone's inattention.

Alternative form of look like something the cat dragged in

(idiomatic) To take up an issue with another person's boss or other superior rather than beginning or continuing to deal with the original person. / (idiomatic) To escape someone's comprehension.

(idiomatic) To become successful on one's own initiative.

(colloquial, idiomatic) An admonition of cowardice, usually said to make someone cease harassing or bullying someone else, especially where the bullied party is physically smaller or weaker than the bully.