While looking for a plan, Our opponent discovers something about his opponent's weapon.  It appears to be pumping water from his mouth, and pushes it back to his gills.  This info may come in handy.  Gilligan now stopped his last attack.

"It would seem our battle has turned into a hunt.  I'll play along."

Gilligan

Attack: Acid rain

Effect: He now shoots his water stream up in the air, causing it to fall like rain.  The liquid appears to have a bit of that acidic gunk in his throat. May have been a good idea to pack a steel umbrella