The phrase "surprise package" refers to something unexpected that is given or received, usually as a pleasant surprise. It can be a gift or an unexpected event that brings joy or excitement. Full definition
This can be considered the real surprise package, as this marks the first time the company is targeting the bigger sized tablet segment. (goodereader.com)
A little surprise package tucked neatly inside the turkey. (theinspiredroom.net)
However, beneath them are a number of potential surprise packages. (footballwhispers.com)