While exploring a dark and spooky cave, The Octonauts find a strange fossil of a powerful prehistoric fish... but it may be more than just a fossil!

When a giant wave hurls Amazon River creatures up into the trees, the Octonauts must get them down safely, without disturbing poison dart frogs who live there.

The Octonauts are exploring Antarctica, when Shellington discovers strange microscopic creatures living under the ice.

When the Octopod breaks down, Tweak and the crew search for a missing part aboard an abandoned prototype of the ship, not realising something lives there.

As newborn baby sea turtles make their way to the ocean, the Octonauts must steer them clear a giant wave and hungry predators.

Captain Barnacles and his niece and nephew, Ursa and Orson, must rescue walrus pups who are stranded on a runaway ice floe, before it collides with a huge iceberg!

The Octonauts must get 2 mantis shrimp to stop fighting before their powerful claw strikes destroy the Octopod.

The Octonauts follow a strange song to a lonely humpback whale.

When a storm washes Peso onto a mysterious, rocky island, he meets a band of lobster-like insects thought to be extinct.

The Octonauts evacuate the creatures living around a reef before a large archway collapses, but one stubborn convict fish refuses to move from her burrow.

The Octonauts journey across a dangerous expanse of ice to help a penguin mother get back to her family.

When a population of crawfish is stricken by illness, the Octonauts race to find a cure.

The Octonauts find a lost flamingo chick separated from his family and they have to return him there before hungry alligators do!

When a hungry tiger shark eats the camera that Tweak's turtle friend Sandy gets in the Octopod, she and the Octonauts must rescue her before it eats everything in its path.

When a huge sunfish enters the GUP-E, Peso and Kwazii must somehow get the large fish out of the Gup. Eventually they find out it's a Sunfish a fish with no fins.

When surfing snails are swept out to sea, it's up to Dashi and the Octonauts to save them.

When Peso gets stranded on a beach with a mass of poisonous snakes after a terrible storm, he and the Octonauts must somehow get them back to the ocean.

Trying to return home from a mission along an African river, the Octonauts have trouble getting past a gang of large, mud-splatting, territorial hippos.

After Shellington crashes the GUP-D for the 3rd time, he and Kwazii team up with moray eels and grouper fish to help pick up the pieces and fix the vehicle before daylight occurs.

While diving down to the Midnight Zone, the Octonauts are attacked by bomber worms.

Dashi teams up with her little sister Koshi to help the Octonauts solve a mysterious disappearance in the Kelp Forest. This is the second episode in which is unknown who sounded the Octo-Alert.

Kwazii takes a vacation on Coconut Island where he gets hit by some coconuts. Then he and the Octonauts must help their old friends the Coconut Crabs discover who's stealing all their coconuts.

Kwazii adopts a baby alligator naming him Nipper, but when it escapes the Octopod, he and the Octonauts must rescue him.

The Octonauts struggle to save a pod of spinner dolphins who seem to be just swimming in their sleep.