Whales have like a +17 tail slap so basically you're like dead if you want to fight plus they have some serious hit dice.
Edited: play by post on 29th Apr, 2010 - 12:34am
Their strength and constitution scores are insane, along with that tail slap and HP. Also I like the Diehard feat they have, pretty funny. I don't know how tough they really are though. If fishermen with wooden spears could kill them ages ago, I think for a well functioning group of PC's it must be just as easy.
Again fighting an animal like this it is best I think to try and grapple it. Or to jump onto its back maybe and attack it from there. I think it would pretty mutch be a hit every time, plus you can't really get tail slapped. Just hope it doesn't dive, if it does my plan turns from brilliant to very bad.