Finn's shrill yelp when something grabbed his leg and pulled did not help him hold his breath in the least. Despite the fact he inhaled what felt like a gallon of water, the dangling upside down helps him breathe again. And scream.

"Help! Get this thing off of me! Kuja!" Kuja's closest, he thinks, which is why he's the one called for. Actually, Finn's very disoriented right now, but not enough to start pawing for his gun. When he shoots (because of course, he's going to shoot at the tentacle monster thing), he misses completely but the bullet ricochets to the target.

Didn't really seem to help, though. "Get off!"