Predator's Swiftness is a druid ability caused by a talent in the Feral spec, [Predatory Strikes]. Each time the druid uses a finishing move (in [Cat Form]), they have a chance for the next nature spell used with a base casting time less then 10 seconds to be instant cast. The chance varies from 7% to 20%, depending on how many talents the druid has in Predatory Strikes.