What curious creatures have eight arms, three hearts, blue blood, and no backbone? Octopuses and squid do! From the tiny Japanese pygmy squid to the huge blanket octopus, these fascinating creatures have weird and wonderful adaptations that help them survive in their ocean home. Learn what makes these many-armed animals so unusual through exciting text, captivating photos, and highly repeatable fun facts. A back matter element features a scientist studying these unusual creatures. Are you ready for underwater oddities?