Is there any idiom or expression for someone who gets something without any effort? [duplicate]

Is there any idiom or expression for someone who gets something without any effort? like a guy got a job without doing anything.. I want a idiom by which i can mock him.

There's the idiom lucky duck or lucky ducky. From the free dictionary:

lucky duck An incredibly lucky person; one who falls into good fortune.
A: "I won another bet in the basketball tournament—that's three in a row now!"
B: "Wow, you lucky duck!"
Just when he was looking to take some time away from work to focus on raising his kids, the company began offering really excellent voluntary severance packages to reduce the number of staff. What a lucky duck, huh?

I'd use this without thinking so was surprised that it has also taken on another meaning to refer to American's who pay no income tax.

If you want something more formal or literary I'd suggest child of good fortune.

There are plenty of references in Google books from the end of 18th century to the present day. eg. Jane Austen's Emma in 1816

Those were Miss Woodhouse's words, were they? And a fine ending—and there is the letter. 'The child of good fortune!' That was your name for him, was it?” “You do not appear so well satisfied with his letter [305] ...

and an edition of Grimm's fairytales in 1997

And the Queen, when she had received the letter and read it, did as was written in it, and had a splendid wedding-feast prepared, and the King's daughter was married to the child of good fortune; and as the youth was handsome and friendly ...

Similar in meaning: fortune's darling or being born under a lucky star.