The Evil Manta has an evil son who wants to follow in his father's evil footsteps, but he shows signs of good. Ariel finds him, and tries to bring that good out of him.

Sebastian's old perfect friend from his childhood comes to town. When Sebastian gets angry because he's so perfect, Sebastian becomes a pawn in Ursula's plan to take over the kingdom.

A poor merboy named Urchin tries to make friends in Atlantica, but when he meets the wrong friends( The Lobster Mobster Squad) it takes a good friend like Ariel to set him right.

The city of Atlantica is a wonderful place to live in, but when Ariel releases an evil manta from imprisonment he spreads the path of prejudice for the creatures of Atlantica. Everybody separates from each, but Ariel and Flounder stay together and work things out in Atlantica.

Once again Sebastian gets kidnapped, but this time a mad scientist kidnaps Sebastian for his crab experiments.

Sebastian thinks that he's the best crab under the sea, but when King Triton wants him to deliver a document to Sharkania he shows his fear.

King Triton thinks that Ariel and Prince Thor would make a perfect couple, but not Urchin so he plays tricks on Thor to make him change his mind about Ariel. The prince gets exasperated and tells his kingdom to have war with Atlantica. Urchin stops it, and Triton explains that he wanted Ariel and Prince Thor to be a couple in the olympic sea games.

After overhearing King Triton talk about him Sebastian thinks that he got fired as the King's trusted advisor. He searches for a new job but gets rehired in the end.

After Ariel's party King Triton feels that he's too old, so his glowing glowfish gets Triton a magical age stone that turns Triton into a little boy called Red. Later on Ariel and Sebastian find out and they trace the jewel to a magic sorcess who only old King Triton can beat.

Ariel and her friends have to babysit some baby mertwins, but when they cause mischief they provide Ariel with some double trouble.

Ariel laughs at everything, even things serious so a sorceror blowfish cast a spell on Ariel so when she laugh's seaquakes will rise.She gets sick of it so when she meets up with thisblowfish she teaches him the power of laughter.

While King Triton's away Sebastian will play. Ssebastian's parents come over,and he lied to them telling them that he is the king of Atlantica. All goes well until King Triton comes home, but when things seem confused Urchin, Ariel, and Flounder get Sebastian out of this mess.

Sebastian is sad because he's a little crab, so Ariel goes to a cave where she becomes a sea witch. She puts a spell on Sebastian that makes him big, but the bigger Sebastian gets the less room their is for everyone in the sea.

Ariel and her little sea friends get King Triton gifts for Father's day. She goes to a cave to get a glowing seashell and they get trapped in by an octupus so Urchin uses the triton to beat him but loses it in the process.

King Triton wants Ariel to learn how to play the calliope, but Ariel wants to learn how to play the harp. She tries to learn the calliope and her bad playing wakes up an old ancient evil sea monster.

Prince Eric drops one of his boots down to the sea, and when Ariel finds it she thinks its a wonderful human thingamajigger, but Triton thinks its dangerous. Soon terrible things start to happen and every sea creature thinks that the thingamajigger is the cause, so every bad guy wants it to take over Triton's kingdom, but Ariel goes to the surface and finds out what they really do.

Ariel wants legs so she can dance but no one believe's in her dream. She gets discouraged until she meets another mermaid called Gabriella who wants to sing so they go to a magical starfish who can make their dreams come true.

Ariel and her big sister Arista get into a big arguement, so they can't go to the carnival. Everything gets all out of hand but when some gators try to rob the kingdom Ariel and Arista learn the true value of sisterhood and teamwork.