Male. A polar bear and the Captain of the Octonauts. He is dignified, calm, and honest. Brave enough to act composed even in dangerous situations. He cares deeply for his crew and always tries to rescue them first. He is strong and excels at swimming and diving. He serves as the leader who directs rescue operations and explorations. He has a strong sense of responsibility and tries to solve every problem to the end. He considers protecting marine life his top priority. He walks and runs on two legs like a human. He is the second oldest among the crew.

Male. An orange cat and a former pirate adventurer. He is brave and loves adventure. He has a personality that makes him the first to step forward in dangerous situations. He has excellent reflexes and is skilled with ropes. He wears an eyepatch over one eye, though the eye underneath is perfectly fine. He is daring but cares for his friends and will protect them to the end if they need help. He enjoys exploring marine life and unknown places. He sometimes acts impulsively but follows the advice of Captain Barnacles and his comrades well. He also walks on two legs.

Male. A penguin and the Octonauts' medic (doctor). He is kind and gentle, treating injured animals with great care. He is a bit timid, but when someone is in danger, he finds the courage to help them until the end. He has extensive medical knowledge and is skilled in first aid and treatment. He has a calm and meticulous personality, so he makes few mistakes. He treasures his comrades and marine life. He is trusted by everyone for his cute and mild-mannered nature. He walks or runs on two legs.

Male. A sea otter and marine biologist. He is curious and loves researching new creatures. He is knowledgeable and has a strong spirit of inquiry. He has excellent observation skills and provides biological information to his comrades. Sometimes he gets too focused on his research. He also walks or runs on two legs.

Male. An octopus and the founder of the Octonauts. He has a scholarly and calm personality. He loves reading books and possesses great wisdom. He advises on operations and provides necessary information. He usually uses a mobile device that looks like a wheelchair. Unlike other members, he doesn't walk on two legs but mostly moves using his tentacles. He appears to be the oldest member. Therefore, the Octonauts crew members speak to Professor Inkling using polite honorifics.

Female. A dog who serves as the photographer and scout. She has a bright and active personality. She is skilled at photography and using computers. She moves quickly and records the situation. She performs her missions calmly. She walks on two legs.

Female. A rabbit and the engineer. She has excellent skills in building and fixing machines. She loves inventing and repairing. She has a lively and positive personality. She maintains the Octonauts' fleet of GUPs. She walks or runs on two legs.

Located underwater, the Octopod is the base and home of the Octonauts. It is a large, octopus-shaped undersea base with a mix of yellow and orange colors. The center is a round main body, with **eight legs (arms)** extending in all directions. At the end of each leg is a small room or connecting passage. At the top, there is an **entrance (launch bay)** where submarines enter and exit. In the front, there is a large round glass window to view the ocean outside. It is firmly situated on the ocean floor and serves as a base for storing and deploying several GUP submarines. The interior contains various spaces including a command room, sick bay, laboratory, kitchen, and bedrooms.

Small creatures. They look like plump radishes(?) with grass sprouting from their heads. Tunip – Cooking, gardening (Leader of the Vegimals) Codish – Assistant cook, ingredient preparation Grouber – Carrying heavy objects Barrot – Fast delivery, errands Tominnow – Swimming, gathering ingredients Pikaj – Growing vegetables, garden maintenance Halibut – Cleaning, transport assistant (They cook fish-shaped biscuits, which are enjoyed by fish, coral, and the crew members.)

- Carrier Crab Carries a sea urchin on its back. Has large, strong claws. Walks sideways quickly. Protects itself with the sea urchin when in danger. Has a cautious but kind personality. - Sea Urchin Has sharp spines all over its body. Moves slowly but protects itself with its spines. Rides on the carrier crab's back to travel together. Lives near underwater rocks or seaweed. May seem prickly at first but cooperates with the carrier crab. In Octonauts, these two show a symbiotic relationship where they might bicker but help each other survive. Others - Cute pink sea cucumbers, jellyfish, clownfish, etc.