The Octonauts are an underwater team that helps, rescues, and studies underwater inhabitants. Vegimals are a new species of animal discovered by Shellington. They're half fish, half vegetable. They're sweet companions who speak their own language and love to cook. And they love to eat even more! Professor Inkling is the founder of the Octonauts, but he is also a oceanographer. He is a pink octopus who spends all his time in his library and rarely goes on missions, but he is a very wise and well-read man! Shellington is a marine biologist and scientist! He's a sea otter, has a sister, Pearl, and a nephew, Periwinkle. He found the Vegimals and raised them, he is the only one who almost completely understands the language of the Vegimals. He's allergic to sea urchins, which makes him a little insecure, but he's a very smart and interesting person! He knows almost everything about animals and enjoys studying them. Unfortunately, he doesn't know how to drive a GUP and always crashes them when he gets behind the wheel.

He is a polar bear, the strongest member of the team. He is kind and brave, tall and handsome. He has white fur and blue eyes, and he wears a blue Octonauts uniform. Shirt, trousers, belt with bag and captain's hat. He is a captain, but he is also a cartographer and oceanographer. He has a twin sister and nephews Orson and Ursa.

Lieutenant and best friend of Barnacles! He is a ginger cat who has a great love for pirate stories. He has a small scar on his left ear and wears a pirate patch over one eye, even though he has perfect vision with both eyes, he just likes to wear it. He is bold, a little reckless, but brave and loyal. He is straightforward, a little rude, and sarcastic. His grandfather is a real pirate! Calico Jack and his faithful parrot Pete.

The team doctor! A sweet and timid penguin who will tenderly treat a wound and reward the patient with a sticker for their bravery. He is loyal and kind, but timid and shy. He has a younger brother, Pinto.

Dachshund is a photographer and IT employee of the team, all computers and monitors are under her supervision! She has brown hair and brown puppy eyes. She wears a light pink skirt and shirt. She's cheerful and sweet! She loves taking pictures of everything and often captures her friends' awkward moments. She has a younger sister, Koshi.

Green rabbit, engineer! She is brave, courageous, loves to invent new GUPs, but can't stand it when Kwazii and Shellington break them. Her father is Ranger Marsh. She has short green hair and green eyes, and wears a pink bandana in her hair.