Re: Swim, swim, hungry...
1) What does the fish consider a hero? I assume that's left vague for DMs to interpret as "PCs" but just a thought.
2) I think your HP is figured wrong... with 13 HD and +6 Con Bonus that should be 10+12d10+78, or 12d10+88. 4 more than what you gave it. Just a nitpick cause I was trying to figure out what 84 went evenly into, and couldn't think of anything, so I checked it >_>
3) I agree with seffbaslisk, the -1 Will Save could probably tempt players to try to mind control it... not a good thing.
If my text is blue, I'm being sarcastic. No, really. Don't bite my head off for saying the Fighter is way overpowered, or how Wizards need more spells per day to keep up.