History Film / TheThirteenthYear

* ParentalAbandonment: Cody has no biological father, and while she's not ''evil'', his mother had to give him up so that he could spend the next thirteen years as a human.

On a bright sunny day, a mermaid leaves her baby son on a human couple's boat while dealing with a zealous fisherman Big John Wheatley (Creator/BrentBriscoe). The child winds up getting adopted by this couple, Whit (Creator/DaveCoulier) and Sharon Griffin (Lisa Stahl Sullivan), and named Cody. Cody (Chez Starbuck) grows up living a fairly normal life, becoming the star of his school swim team and dating a girl named Samantha (Creator/CourtneeDraper). But then he begins to experience weird things shortly after turning thirteen years old, such as constantly feeling thirsty and growing scales and fins when he's splashed with water. With the help of his biology class tutor (and Big John's son) and eventual best friend Jess Wheatley (Justin Jon Ross) just what is happening to him.

On a bright sunny day, a mermaid leaves her baby son on a human couple's boat while dealing with a zealous fisherman (Creator/BrentBriscoe). The child winds up getting adopted by this couple, Whit and Sharon Griffin, and named Cody. Cody grows up living a fairly normal life, becoming the star of his school swim team and dating a girl named Samantha. But then he begins to experience weird things shortly after turning thirteen years old, such as constantly feeling thirsty and growing scales and fins when he's splashed with water. With the help of his biology class tutor and eventual best friend Jess Wheatley (who happens to be the mermaid-obsessed fisherman's son), he starts investigating just what is happening to him.

* TransformationFiction: The premise of this film is that once [[ThirteenthBirthdayMilestone the main character became 13 years old]], he slowly transforms into a merman.

* BigNo: From Cody, when his real mom is about to be snared by Big John's net.

* BittersweetEnding: Cody goes off to be with his real mom but leaves his adoptive parents and friends behind. However, Cody promises that he will return before the next school semester starts in order to complete his education, which implies that his transformation may not be completely irreversible, so this is mild.

* MamaBear: Cody's real mom. And she protects Cody from Big John (well, she tries). When she witnesses Cody collapsing in pain as his tail begins to form, her first instinct is to help him.

* ParentsAreWrong: Cody wants to live under the sea and be with his real mom. Sharon vetoes this, but eventually relents and realizes that Cody has to be free to live his own life.

* MamaBear: Cody's real mom. And she protects Cody from Big John (well, she tries).

* GranolaGirl: Sharon, Cody's adoptive mom, shows shades of this, such as disparaging capitalist society and not trusting most forms of medicine.

* ThirteenthBirthdayMilestone: The movie revolves around a boy turning into a mermaid upon his 13th birthday and attaining a PubertySuperpower.

On a bright sunny day, a mermaid leaves her baby son on a human couple's boat while dealing with a zealous fisherman. The child winds up getting adopted by this couple, Whit and Sharon Griffin, and named Cody. Cody grows up living a fairly normal life, becoming the star of his school swim team and dating a girl named Samantha. But then he begins to experience weird things shortly after turning thirteen years old, such as constantly feeling thirsty and growing scales and fins when he's splashed with water. With the help of his biology class tutor and eventual best friend Jess Wheatley, he starts investigating just what is happening to him.

** Cody acts a bit like a standard jerk jock before he goes through CharacterDevelopment, being a top sport swimmer who doesn't education seriously and looks down on nerds like Jess. It isn't until he needs Jess to help boost up his failing grade in biology and later safely discuss his merman-puberty experience that Cody starts to realize how much of an ass he was.

* StuffBlowingUp: Cody accidentally makes the scoreboard at the swim meet explode, which somehow doesn't kill anyone. Mostly likely because everyone was at a safe distance.

* SurprisinglyRealisticOutcome: You might think that Cody intends to leave his human allies forever, but Sharon tells him what the mermaid told her that she promises to have him return on land to finish his schooling, rendering the film's BittersweetEnding to a mild one.

* AudienceSuperiority: We find out Cody is a merman and who his mother is extremely quickly, but it takes the characters a good chunk of the movie to figure it out.

** Cody acts a bit like a standard jerk jock before he goes through CharacterDevelopment. Top sport swimmer, not taking education seriously, and looking down on nerds like Jess. It isn't until he needs Jess to help boost up his failing grade in biology and later safely discuss his merman-puberty experience that Cody starts to realize how much of an ass he was.

* ThirdPartyStopsAttack: Both Jess and a teacher are able to break up Cody and Jess' fight.

** Cody mentions Ariel from ''WesternAnimation/TheLittleMermaid'' when he brings up his electrokinetic abilities.