- Fiesta Trio
- Pirate Pig
- Pirate Piggies
- Clam (debut)
- Mariana the Mermaid (debut)
- Garbage Octopus
- Sea Shell Bridge
Dora must return a magic crown back to a mermaid named Mariana in Mermaid Kingdom and get past a mean octopus who dumps garbage all over the kingdom.
The episode starts where Dora and Boots were at the beach. They were cleaning up the beach because it is Clean Up The Beach Day. They were looking for garbage on the sand and took a juice box off a crab's head. After looking for garbage, a very special clam told Dora and Boots about Mermaid Kingdom. He told them a story about Mariana the Mermaid but she and her friends were in trouble because a mean octopus dumped garbage all over the Mermaid Kingdom and it could dissappear. He told them that Mariana discovered a magic crown put it on, made a wish and all the garbage dissappeared and the kingdom sparkled. But, one day a wave swept the crown away and Mariana needed Dora and Boots' help because the octopus was back and the garbage was making the mermaids and mermen sad and sick. Mariana tells Dora and Boots that their Mermaid Kingdom is disappearing under all the dirty garbadge and she needs their help.
Dora and Boots saw the magic crown on the sand and Dora picked it up. Map says that they had to go over Sea Shell Bridge, across Pirate Island, past the Silly Sea and then the Mermaid Kingdom.
Places in episode
- This is the last episode to find Map.
- Season 7 episode "Dora's Rescue in Mermaid Kingdom" serves as the sequel of this episode.
- This is the first double-length episode where Dora says "check" and a red check-mark is placed on what squares which shows the name of the place Dora and Boots went through.
- This is not the last episode for the original cast, namely Kathleen Herles (Dora), Harrison Chad (Boots), Sasha Toro (Backpack), Jake Burbage (Benny), and Jose Zelaya (Tico) to act before their departure due to their age, but the voices of Map, Swiper (both by Marc Weiner) and Diego (Jake T. Austin) will still be present for at least the next season.
- Dora turns into a mermaid just as she puts on the mermaid crown. When she takes it off, she turns back into herself.
- This is the last episode where the blue cursor clicks on Dora at the end of the episode. After this, a fade-out effect will take its place for the rest of the series.
- However, Map and Swiper are still voiced by Marc Weiner and they are the only ones not to have new voice actors.
- This is the last episode to "Character Find" when the closing credits appeared.
- This is the last episode of Season 4.
- This is the last episode to premiere in 2007.
- The 2005-2009 Nick Jr. Productions Logo which used the 1999-2005 Nick Jr. Productions music from "Dora's World Adventure" was used again for this episode.
- This is the final time the show uses the 2005-2009 Nick Jr. Productions Logo.
- Split screen airings of this episode use the 1999-2005 Nick Jr. Productions Logo at the end instead.
- This is the 5th episode that lasts for over 30 minutes.
- This is the 101st episode of the show.
- In this episode, there are four squares instead of three.
- The name of this episode was released as a video game for the Nintendo DS.
- Mariana the Mermaid will later appear on a Dora and Friends episode titled Magical Mermaid Adventure.
- Goof: when Dora and Boots finished helping Swiper clean off the whale they run the opposite way to go to Pirate Island.
- The grown-up voice Dora has in Dora's Dance to the Rescue and Dora's World Adventure was also debuted in this episode. This will be the last instance that Dora uses her grown-up voice.
- The graphics has been changed in this episode just like the background and Dora having smaller eyes. All of these things have been used in Season 5.
- This is apparently the first episode in which the pattern at the bottom of Dora's shoes has changed.
- Dora and Boots' season 5 look has been debuted in this episode.
- The episode premiered exactly 5 years after Click! premiered.
- This is the fourth episode to use the extended version of We Did It. The other three are Dora's Pirate Adventure, Dora's Dance to the Rescue, and Dora's World Adventure.
- When Dora and Boots sing the Travel Song, they list four places instead of three and they do not say "Come on, say it with us!" to begin the song. Boots is the only one clapping three times after asking "Where are we going?" since Dora is holding Mariana the Mermaid's magical crown throughout the episode. Also, the fourth "Where are we going?" is asked in Spanish.
- Map is the last character to get Character Find.
- This is the last episode featuring a Character Find during the end credits.
- Isa does not appear in this episode.
- This is the only episode in the series in which Dora and Boots explicitly asked Swiper to swipe. It is also mentioned in the "We Did It" song.
- This is the last episode to feature Explorer Stars in the introduction.
- This is the first and only time that Dora and Boots told Swiper to swipe the garbage off the whale’s eyes.
|Dora the Explorer Season 4|
|Dora's Fairytale Adventure | Daisy, La Quinceañera | Star Catcher | La Maestra de Música | The Shy Rainbow | Star Mountain | Big Sister Dora | Super Babies | Catch the Babies | Dora's Got a Puppy | We're a Team! | Super Spies 2: The Swiping Machine | A Crown for King Juan el Bobo | The Mixed-Up Seasons | Best Friends | Dora's Dance to the Rescue | Save Diego | Dora's First Trip | Baby Jaguar's Roar | Dora's World Adventure! | Boots to the Rescue | Baby Crab | Dora Saves the Mermaids|