grab bag
grab bag {n.}
1. A bag from which surprise packages are chosen; a bag in which there are many unknown things.
The woman paid a quarter for a chance at the grab bag.
The children brought packages to be sold from the grab bag at the school carnival.
2. A group of many different things from which to choose; a variety.
The TV program was a grab bag for young and old alike.
Categories:
Source: A Dictionary of American Idioms