Thomas' Adventures of The Little Mermaid is a Thomas & Friends/Disney Crossover film created by 76859Thomas. A remake will appear on Google Drive in the near future.
A sixteen-year-old mermaid princess named Ariel is dissatisfied with underwater life and curious about human life on land. With her best friend Flounder, Ariel collects human artifacts and goes to the surface of the ocean to visit Scuttle the seagull, who offers very inaccurate knowledge of human culture. She ignores the warnings of her father King Triton, the ruler of Atlantica, and his adviser and court composer Sebastian that contact between merpeople and humans is forbidden.
One night, Ariel, Flounder and an unwilling Sebastian travel to the ocean surface to watch Prince Eric celebrate his birthday. Ariel soon becomes enamored with Eric. A violent storm wrecks the ship and tosses Eric overboard, but Ariel saves him and brings him to shore. Ariel sings to him, but quickly leaves as soon as he regains consciousness to avoid being discovered. Fascinated by the memory of her voice, Eric vows to find who saved and sang to him, and Ariel vows to find a way to join him and his world. Noticing a change in Ariel's behavior, Triton questions Sebastian about her behavior and learns of her love for Eric. Frustrated, Triton confronts Ariel in her grotto, where she and Flounder store human artifacts, and destroys most of the objects with his trident to her dismay. After Triton leaves, two eels named Flotsam and Jetsam convince Ariel to visit Ursula the sea witch.
Ursula makes a deal with Ariel to transform her into a human for three days in exchange for Ariel's voice, which Ursula puts in a nautilus shell. Within these three days, Ariel must receive the "kiss of true love" from Eric; otherwise, she will transform back into a mermaid and belong to Ursula. However, if Ariel gets Eric to kiss her, she will remain a human permanently. Ariel agrees and is then given human legs and taken to the surface by Flounder and Sebastian. Eric finds Ariel on the beach and takes her to his castle, unaware that she had saved his life earlier, he and his staff assuming her to be a mute shipwreck survivor. Ariel spends time with Eric, and at the end of the second day, they almost kiss but are thwarted by Flotsam and Jetsam. Angered at their narrow escape, Ursula disguises herself as a young woman named Vanessa and appears onshore singing with Ariel's voice. Eric recognizes the song and, in her disguise, Ursula casts a hypnotic enchantment on Eric.
The next day, Ariel finds out that Eric will be married to the disguised Ursula. Scuttle discovers that Vanessa is actually Ursula in disguise, and informs Ariel who immediately pursues the wedding barge. Sebastian informs Triton, and Scuttle disrupts the wedding with the help of various animals. In the chaos, the nautilus shell around Ursula's neck is broken, restoring Ariel's voice and breaking Ursula's enchantment over Eric. Realizing it was Ariel that saved his life, Eric rushes to kiss her, but the sun sets and Ariel transforms back into a mermaid. Ursula reveals herself and kidnaps Ariel. A furious Triton confronts Ursula and demands that she release Ariel, but the deal is inviolable. At Ursula's urging, the king agrees to take Ariel's place as Ursula's prisoner, giving up his trident. Before Ursula can use the trident, Eric distracts her with a harpoon. Ursula tries to strike down Eric, but Ariel attacks Ursula, who inadvertently kills Flotsam and Jetsam. In her rage, Ursula uses the trident to grow into monstrous proportions.
Ariel and Eric reunite on the surface just before Ursula grows past and towers over the two. She then gains full control of the entire ocean, creating a storm and bringing sunken ships to the surface. Just as Ursula attempts to kill Ariel, Eric steers a wrecked ship into Ursula, stabbing her with the ship's splintered bowsprit. With Ursula destroyed, Triton and the other polyps in Ursula's garden revert into their original forms. Realizing that Ariel truly loves Eric, Triton willingly changes her from a mermaid into a human and blesses her marriage to Eric.
- Salty is guest starring in both versions of this film and is revealed to be an old friend of Scuttle.
- The Digidesten and their Digimon, Woody Woodpecker and Ttark are guest starring in the upcoming remake of this film.
- This film marks the first debut of Salty from Thomas & Friends.
- Winnie the Pooh, Ash Ketchum and Team Rocket were mentioned in this film.
- Thomas, Twilight Sparkle, the whole gang and Salty are able to breathe underwater due to Twilight's magic making them impervious to drowning.
- The song of the credit is Part of Your World sung by Jessica Simpson.
- Flashback is used from Thomas the Tank Engine Meets Peter Pan.
- In the song "Kiss the Girl", Thomas and the whole gang are all shown to be singing the song with Sebastian.
- My Little Pony: Equestria Girls, Thomas & Friends: King of the Railway, Thomas & Friends: Series 17, My Little Pony Friendship is Magic: Series 4 and The Little Mermaid: Diamond Edition were all released in 2013.
- Like in Pooh's Adventures of The Little Mermaid (in which Winnie the Pooh and his friends met Ariel for the first time) and in the upcoming film Bloom's Adventures of The Little Mermaid (in which Bloom and her friends will meet Ariel for the first time). this film will mark the first time Thomas and his friends met Ariel.
- The Storylines continues in Thomas' Adventures of The Little Mermaid 2: Return to the Sea.