Ruby Gillman: Teenage Kraken (Full Fandub)

In the seaside town of Oceanside, 16-year-old[9][10] Ruby Gillman lives with her family, trying to fit in with humans despite being krakens. Her mother Agatha forbids her from going to prom because of its location being on a ship in the ocean. At Oceanside High School, Ruby initially refuses, but her friends Margot, Trevin, and Bliss convince her to ask out her crush Connor. Before she can ask, she accidentally knocks Connor into the water. Ruby jumps in and saves him, but Connor believes he was saved by the new girl Chelsea Van Der Zee who tries to befriend Ruby. Ruby notices bioluminescent suction cups on her fingers and hides in the library. She attempts to call Agatha, but decides against it. To her confusion and horror, she transforms into a giant kraken and accidentally destroys the library after being startled by the librarian.

Ruby panics after being spotted by Chelsea and runs to the lighthouse to hide. Agatha notices and chases her, reuniting with her brother Brill along the way, who had been sent to retrieve Ruby by her grandmother after she sensed the Pulse emitted by Ruby’s transformation. Finally catching up with her, Agatha calms the distressed Ruby down and she shrinks down to her normal size. At the house, Arthur, Ruby's father, and Sam, Ruby's little brother, discover Ruby's transformation. Agatha explains how Ruby’s earlier mishap triggered the transformation and that she also turns into a giant kraken.

Angered that Agatha withheld the truth from her, Ruby sneaks out to meet her grandmother, the Warrior Queen of the Seven Seas, with a reluctant Brill's help. Grandmamah reveals to Ruby that she is a princess and next in line to take the throne, to her shock. She also explains that outside the leviathans and the Umibōzu, the mermaids are actually the most malevolent creatures in the seas and how Nerissa found a powerful trident called The Trident of Oceanus to rule the ocean. Agatha, the greatest Kraken warrior, trapped them for all eternity. Ruby declines the throne, but is thankful to have finally learned the truth. On her way home, she is attacked and almost killed by an elderly sailor and Oceanside tour guide, Gordon Lighthouse. Chelsea, who reveals she is a mermaid, saves and helps Ruby escape, much to Gordon's disappointment.

Ruby tries to return to her normal life, but footage of her in her Kraken form becomes viral. She has a "Super Sea Girl Ditch Day" with Chelsea, who tells her that her mother, the mermaid Queen Nerissa, was supposedly killed trying to retrieve the Trident. She asks Ruby to get it to help unite the Krakens and Mermaids, so Ruby trains with Grandmamah to be powerful enough to get it.

On prom night, Ruby tells her mother about Chelsea, but Agatha, disappointed and outraged that Ruby made friends with a mermaid, forbids her from seeing her grandmother, leading to a frustrated Ruby running back to the ocean to grab the Trident for Chelsea while Agatha confronts Grandmamah, with the latter stating Nerissa never had a daughter and the former realizing Chelsea is not who she says she is. Ruby succeeds in retrieving it but is betrayed by Chelsea, who reveals that she is Nerissa and uses Ruby to help her reclaim the trident to exact her revenge on the Krakens. Nerissa sheds her disguise and traps Ruby before going to destroy Oceanside. Agatha and Grandmamah try to fight her off while Brill finds a demoralized and wounded Ruby. After he encourages her, she goes to the surface to stop Nerissa. Nerissa overpowers Grandmamah and Agatha but is confronted by Ruby, who engages her in a duel over the trident, revealing her secret to her friends and Connor.

Nerissa gains the upper hand, but Ruby disarms her, realizing that the Trident can be destroyed with enough power. Ruby attempts to reason with Nerissa to no avail, so she, Agatha and Grandmamah combine their laser eyes to destroy the trident, defeating Nerissa and shrinking her to her normal size, where Gordon cages her. Ruby reconciles with her mother, reunites with her friends, and asks Connor out to prom, which he accepts, while Agatha and Grandmamah also reconcile.

Sometime later, everyone returns to their normal lives. The Gillmans become more popular and successful than before. Ruby and Connor become a couple and she becomes the protector of Oceanside. Ruby then enters the sea upon being informed by Uncle Brill that a Devil Whale is heading towards the Kraken Kingdom.