What is a teenage kraken to do? Well, she could try going away, which I’m sure will happen soon. Dreamworks’ “Ruby Gillman, Teenage Kraken” tells the story of a not-quite-human-looking adolescent kraken, which according to one source is an “enormous, mythical sea monster said to appear off the coast of Norway.” In “Ruby Gillman, Teenage Kraken,” the title character Ruby (Lana Condor) is a “mathlete,” who does not fit in at her seaside high school, which could be because she is blue with fins for ears.

Ruby and her somewhat less outlandish best friends, including Margot (Liza Koshy), have made a pact not to attend prom. But when Ruby learns that Margot and the others are going to prom, she has a crisis of identity. You see Ruby, her real-estate sales-working mother Agatha (Toni Collette), father Arthur (Coleman Domingo), who runs a company called Bottled Up, little brother Sam (Blue Chapman) are all krakens. They are no longer kraken-sized because they no longer live in the ocean (or ever go in it). If they do, they will resort to their true selves. Ruby and her family try to brush off any questions about their odd appearance by saying, “We’re from Canada.” One day, Ruby tries to rescue Connor (Jaboukie Young-White), a skater she has a crush on and with whom she’d like to go to prom, who falls into the sea. In the water, she grows. It’s kind of “The Little Mermaid” in reverse.

On one level, “Ruby Gillman, Teenage Kraken,” like the far superior Pixar effort “Turning Red,” is a metaphor about a young woman experiencing puberty and the first pangs of love. Instead of a red panda, Ruby becomes the aforementioned mythical creature. She also discovers that a classmate named Chelsea Van Der Zee (Annie Murphy), who bears a strong resemblance to a certain Disney animated heroine named Ariel, also has a secret about her true self. In the ocean in her kraken form, Ruby also meets her regal “grandmamah” (Jane Fonda), the Queen of the Krakens, and is informed that she is the princess and next in line, that her mother was a mighty kraken warrior and that krakens and mermaids are deadly enemies. Ruby also learns of an object of power known as the Trident of Oceanus.

“Ruby Gillman: Teenage Kraken” has a talented voice cast. But unlike, say, “The Little Mermaid,” which is loosely based on a fairy tale by Hans Christian Andersen, this kraken gobbledygook is a bit hard to take (laser eyes?). We are reminded that people used to believe krakens were “ship killers.” But the mythology is a bit thin compared to the lore concerning mermaids and sirens.

Co-directed by Kirk DeMicco (“The Croods”) and first-timer Faryn Pearl, “Ruby Gillman, Teenage Kraken” is pleasant enough, however far-fetched. But writers Pam Brady (“South Park”), Brian C. Brown (“Briarpatch”) and Elliott DiGiuseppi (“Lucy in the Sky”) try so hard to wring some humor from the story that it is exhausting. Every five minutes or so, we get a bad pop song, accompanying another uninspired montage. The underwater kingdom is bedazzled. We are reminded more than once that prom is “a post-colonial, patriarchal construct,” which would be funny, if people didn’t talk like that. While Ruby’s friends make scant impression, one of the most memorable characters is an old salt named Gordon Lighthouse, who has a scuttling crab sidekick and is voiced by Will Forte.

(“Ruby Gillman, Teenage Kraken” contains action-film violence, rude humor and mature themes)

PG. At the AMC Boston Common, AMC South Bay and suburban theaters.