Near impossible to hit without completing Bridge Puzzle
Impossible to be harmed by when the Bridge raises
Only appearing in the Akropolis Tower bridge, the Bass is a mutated fish NMC and really, if you solve the puzzle for the bridge, they are of zero consequence. The solution to the puzzle is in the room where you use the two keys and despite the "nature" of the puzzle, you do not need any knowledge of music. For newcomers, the code is 561.
If the puzzle is not solved, Bass can deal a lot of damage to Aya as she walks through the water as they take passes at her. Also, it is impossible to attack them as their attacks cause Aya to recoil and they are fairly fast.