grab bag 
noun North American
1A lucky dip in which wrapped items are chosen by people at random.For her, the box is a useless and impersonal thing, like the random presents pulled out of a grab bag....
- I asked her if the wrapped presents were to be chosen randomly by each person from a grab bag.
- For a limited time, we have holiday grab bags available for a great price with fun mystery prizes.
1.1An assortment of items in a sealed bag which one buys or is given without knowing what the contents are.The documents spell out a corporate shopping list, a grab bag of public and private services which European companies would like to get their hands on....
- Every day the quarantine officials find a grab bag of seeds, plants and fungi.
- It's a veritable grab bag of surprises as nothing's really been nailed down yet.