Under the sea! Under the sea! Singing aside, you are now underwater and the first part of this level is similar to the one where you were riding General Rat inside of General Snake. When the stage begins, use R2 on both the God of the Sea and the squids to get the SUSHI and SQUID HEADS, respectively. Note that it's important you try and keep the Sushi Head for the Weaver boss fight at the end of this level, as it makes things a lot easier.
When you're ready, jump on the squid and get riding. Unlike the sequence with Rat, there will be plenty of obstacles in the way, including sea urchins you have to crouch under and jellyfish that function as trampolines. The yellow- colored shrimp function as a speed boost, some of which are needed, so don't pass them up. It doesn't matter which direction you go at the first seam cut, so just continue going until you hit the second screen.
Things start getting a little more challenging here, with anglerfish being thrown in, which you must jump over when you get close (they'll jump up and attack). When you see crabs, do not jump and just keep going normally and take the upper path at the seam cut. The three jellyfish can be hit with R2 and give up the JELLYFISH HEAD for Kutaro.
At the start of the third screen, you can use the Shark Head's action if you still have the head, giving you a chance to bypass some of the beginning sections. Otherwise, you will have a giant anglerfish chasing after you, shooting little ones at you that you will need to jump over. When you get to a piece of ship, there will be an icon there to use the Squid Head's action, which will remove the giant anglerfish from the scene. You'll get thrown into the fight with the Kraken Weaver.
Kraken Weaver
The fight with the Kraken Weaver has multiple stages and he's certainly large. He knocks you down into a pit below, with some anglerfish and other enemies and hazards. Bomb the clam shell to make some bubbles appear, which you can use to get to the platforms above, where you can kill the Grubs and then bomb the mines. This will get you to the Kraken tentacle and attack it.
Attacking the tentacle will launch Kutaro into a QTE that will take out one of the three hits needed to down the Kraken. He'll try to suck you in and if he catches you, mash X to get away. Find the tentacle with the hook on it, then use the Pirate's Head to get toss downed into another pit. Use the anemone to get to the trampolines and then to the next tentacle to cut, launching the second QTE in the battle.
Note that during the ascent in the second pit, you likely saw an icon to use the Sushi Head, which will replace all the hazards with pieces of food. This holds true for the third pit as well, making it a lot easier to get past them all. He'll launch some urching that roll around the screen, some on floor level and some in glasses; jump over the ones on the ground and go underneath the others.
Once again, take out the Grubs and then find the tentacle with the hook on it. Avoid the hazards in the first section of the third pit, then use the smoke left behind by the bombs to reach an anemone that will launch you to the tentacle. The final QTE will start that will finish off the Kraken, as well as get you the OCTOPUS HEAD.
