Yeah, found it. I hadn't been through that stretch of Open Waters for a long time, and had neglected to mark the current on my map. Easiest boss so far. Now to go back exploring and seeing where I can use nature and fish forms...
9) There are a bunch of yellow, spikey, jumping plants(?) in the Kelp Forest. What is their significance? They're super-easy to avoid, they don't shoot anything at you, you can't eat them (or I get hurt every time I try, at least), and they never appear to drop any items.
10) Tadpole-thingies. I found one of these in a house in Mithalas, and it attached to me and gave me constant life regeneration until I moved to the next zone. I found a small cave with more of them in the Kelp Forest, but they wouldn't attach to me in any form, and singing didn't seem to help either. Anyone know what I'm talking about? How do you get them to attach?
11) Where the heck do you find a Sea Cake?! I have five or six cake recipes. ALL of them require sea cake as a base ingredient. I have every form up to the fish now (which, incidentally, answers my question about whether or not you can have a creature form!) and have yet to find a single sea cake anywhere.