The Giant Spider Crab
Plot:
Humuhumus: When the Octopod's waterworks are flooded with frightened Humuhumu fish, the Octonauts have to find a way to flush them out! Giant Spider Crab: Kwazii is spooked when he spots what looks like a giant underwater spider! But it turns out to be a very old Spider Crab who needs the Octonauts' help!