Breshan Bass is an enemy in Final Fantasy XIII that is fought in Lake Bresha. They are much more dangerous than their counterparts, albeit appearing in smaller numbers. The party should keep a Sentinel and/or Medic present for most of the fight.
Bass is a name shared by many different species of fish encompassing both freshwater and marine species. All belong to the large order Perciformes, or perch-like fishes, and the word "bass" comes from Middle English bars, meaning "perch."