Amazon offers Prime members Imploding Kittens: The First Expansion of Exploding Kittens for $12.74 with free shipping. That's the lowest price we could find by $2. It requires the Exploding Kittens base game to play. This expansion pack comes with 20 new cards (illustrated by the guy who does The Oatmeal), and expands the core deck from five to six players. A human-sized "Cone of Shame" turn indicator is also included.