Meet Grimpy! He's a dumbo octopus, and he's taking us on a tour of the whole cephalopod class-underwater creatures such as cuttlefish, nautiluses, octopuses, and squids. Grimpy knows all about what makes these many-armed marvels so special, like how the coconut octopus uses tools or the cuttlefish talks with color! It seems like every creature has a special ability-except him. When Grimpy gets stuck on everything a dumbo octopus can't do, the other...