From the back of the box:
The combo box contains both the basis Spank the Monkey game and the Monkey Business expansion. Exclusive to the box you will also find a brand new red monkey dice with the monkey logo on one side, and over-sized Monkey Height card and monkey marker to keep track of the monkey's height. In addition, the combo box also features some new artwork and cards, including the Gigantoskop previously only available as download from Gigantoskop web site.
In short: With the Spank the Monkey combo box you can go absolutely bananas.