E1 - The Siphonophore

Aired: September 04, 2013

Kwazii and Dashi become entangled in a strange deep-sea creature - a siphonophore.

E2 - The Water Bears

Aired: September 05, 2013

The gang ventures into a red-hot lava tube to rescue a tiny water bear that does not seem to mind the heat at all.

E3 - The Cone Snail

Aired: September 06, 2013

Peso sets out to save the day when a cone snail invades the octopod and picks off the crew one by one with its dangerous harpoons.

E4 - The Artificial Reef

Aired: September 09, 2013

When an underwater storm destroys a small reef, Tweak and her crew try to convert the Gup-F into an artificial equivalent.

E5 - The Humpback Whales

Aired: September 10, 2013

When a sardine swallows the key to a treasure chest, a humpback whale helps Kwazii track it down.

E6 - The Pelicans

Aired: September 11, 2013

When a floating garbage patch endangers a flock of pelicans and other sea creatures, the Octonauts and the birds work together to clean it up.

E7 - The Sea Pigs

Aired: September 12, 2013

The Octonauts must stop a huge herd of sea pigs before they march blindly into the Mariana Trench - where there will be no access to food. But things get chaotic when Tunip goes missing!

E8 - The Yeti Crab

Aired: September 13, 2013

As Tweak tests the Gup-X deep down in the Midnight Zone, a yeti crab cuts a vital electrical wire in the ship and cuts off all power, endangering itself and the Octonauts.

E9 - The Barracudas

Aired: March 10, 2014

Shellington and the Vegimals' mission to replant a mangrove forest is put in peril by a school of toothy barracudas.

E10 - The Duck-Billed Platypus

Aired: March 11, 2014

While rescuing river creatures after a storm, the Octonauts find a strange egg and come under attack by stinging platypuses.

E11 - The Sea Skaters

Aired: March 12, 2014

When Kwazii gets lost at sea aboard the tiny octo-ski, he meets a flotilla of even tinier sea skaters - the only insects who live on the ocean.

E12 - The Mudskippers

Aired: March 13, 2014

The Octonauts attempt to keep the peace amongst a trio of mudskippers whose home has been flooded.

E13 - The Harbour Seal

Aired: March 14, 2014

When Peso's patient, a remora fish, mysteriously disappears, the Octonauts enlist a unique undersea detective - a harbour seal.

E14 - The Lion's Mane Jellyfish

Aired: March 17, 2014

A lion's mane jellyfish gets its long and stingy tentacles tangled in the bubble engine, unintentionally flooding the Octopod and causing havoc.

E15 - The Red Rock Crabs

Aired: March 18, 2014

When Shellington and the crew try to gather some skittish crabs who have drifted away from home, they get help from some old friends.

E16 - The Sea Sponge

Aired: March 19, 2014

A sea sponge that houses other sea creatures in its pores suffers from a mysterious illness and Peso must figure out the cause.

E17 - The Immortal Jellyfish

Aired: March 20, 2014

Shellington and the Octonauts try to track an unusual creature: a jellyfish that can transform from old to young repeatedly - and live forever!

E18 - The Urchin Invasion

Aired: March 21, 2014

The Octonauts head to the kelp forest to visit Shellington's sister, Pearl, and her newborn son Periwinkle - only to find the forest endangered by an infestation of kelp-eating urchins!

E19 - The Hammerhead Sharks

Aired: September 21, 2015

The Octonauts meet some hammerheaded sharks, however, they can't sleep too well because Shellington and Professor Inkling have been arguing about who is smarter that they are no longer friends.

E20 - The Loggerhead Sea Turtle

Aired: September 22, 2015

After an undersea tremor separates the Gup-X and its crew, Barnacles seeks guidance from a mysterious sea turtle.