The second expansion for Catastrophic adds 40 new cards to the game around an aquatic theme. You can now enhance your species with fins, scales, blubber to create aquatic animals for the first time, and your land-animals can also be enhanced with traits that improve water retention for dry climates. However you will also need to face new dangerous events including rising sea levels and nuclear winter! The expansion introduces new interaction cards that help your new species form shoals, or even drift on ocean currents. The expansion can be used with the base Catastrophic game or in combination with the first expansion, Birds & Bees. —description from the designer