Hydration (Merfolk)

Category ancestryfeature;

Your body requires you to return to aquatic environments at least once in a 24-hour period. After the first 24 hours outside of water, you take a –1 status penalty to Fortitude saves. After 48 hours, you struggle to breathe air and begin to suffocate until returned to water.

Source: Pathfinder Howl of the Wild ORC