Keep an eye on the Golden Book. It provides free spins and has the potential to grow in size to pay out generously. The notion of expanding symbols runs throughout the Book of Cats. A standard symbol is selected randomly to grow in size during the free spins, and winning symbols on the particular sixth row can also grow.
The "Golden Book" symbol acts as both the scatter and the wild symbols. The gamble feature can be selected as the "double" or "nothing" option.