I'm gonna knock him out!!!
Succeed in a special attack against Arlong.
Only possible in Episode 3 of the Main Log when you face of against Arlong at the end of the stage.
When Arlong has 2 health bars lefts he will start swimming in the water. Avoid his attacks and at a certain moment you will have the chance to catch him with X then finish it by filling a bar by rotating the left analogue to the left.