Esio Trot is a 1990 children's novel by British author Roald Dahl.^[1] The title is an anadrome of "tortoise". It was the last of Dahl's books to be published in his lifetime; he died just two months later.

Unlike other Dahl works (which often feature tyrannical adults and heroic/magical children), Esio Trot is the story of an ageing, lonely man (Mr Hoppy), trying to make a connection with a person that he has loved from afar (his widowed neighbour, Mrs Silver).^[2]

In 1994, Monty Python star Michael Palin narrated the English language audiobook recording of the book.^[3] In 2015 it was adapted by Richard Curtis into a BBC television film, Roald Dahl's Esio Trot, featuring Dustin Hoffman and Judi Dench as the couple, with James Corden narrating.^[4] Geoffrey Palmer narrated a second English-language recording in 2023.^[5]

Mr. Hoppy is a shy elderly bachelor who lives alone in an apartment, tending to his many plants, which have been the center of his life since he retired from his job in a bus garage several years before. For many years, he has had a secret love, the widowed Mrs. Silver. She lives in the flat below his, and he frequently leans over his balcony and exchanges polite conversations with Mrs. Silver, but his courage fails him whenever he prepares to hint at his true feelings for her.

Mrs. Silver has a small pet tortoise, Alfie, who is the center of her world. One morning, Mrs. Silver mentions to Mr. Hoppy that even though she has owned Alfie for many years, he has only grown a tiny bit and has gained only 13 ounces (370 g) in weight. She confesses that she wishes she knew of some way to make her little Alfie grow into a larger, more dignified tortoise. Mr. Hoppy suddenly thinks of a way to give Mrs. Silver her wish and win her heart.

Mr. Hoppy tells Mrs. Silver that he — in fact — knows a way to make a tortoise grow bigger. He writes the following words on a slip of paper, and lowers it down to Mrs. Silver:

ESIO TROT, ESIO TROT,
TEG REGGIB REGGIB,
EMOC NO, ESIO TROT,
WORG PU, FFUP PU, TOOHS PU,
GNIRPS PU, WOLB PU, LLEWS PU!
EGROG! ELZZUG! FFUTS! PLUG!
TUP NO TAF, ESIO TROT, TUP NO TAF,
OG NO, OG NO, ELBBOG DOOF.

Mr. Hoppy explains that these magic words, when whispered in Alfie's ear three times a day, will cause Alfie to grow bigger and bigger. Mrs. Silver is doubtful but agrees to try. (The words are, reversed, Tortoise, tortoise, get bigger bigger! Come on, tortoise, grow up, puff up, shoot up! Spring up, blow up, swell up! Gorge! Guzzle! Stuff! Gulp! Put on fat, tortoise, put on fat! Go on, go on, gobble food!)

Over the next few days, Mr. Hoppy carries out the second part of his plan. He visits every pet shop in the city, and buys many tortoises of various sizes, but none that weigh less than 13 ounces (370 g). Mr. Hoppy brings all the tortoises back to his flat and installs them in a makeshift corral in his living room. Next, Mr. Hoppy builds a special tool to help him snatch the tortoise from Mrs. Silver's balcony. He fastens a handle to the end of a long metal tube, and a tiny claw at the bottom. By pulling the handle, the arms of the claw gently open and close.

The following day, when Mrs. Silver leaves for work, Mr. Hoppy selects a tortoise from his living room that weighs exactly 15 ounces (430 g). He carefully picks Alfie up from the lower balcony and exchanges him with the new tortoise. When Mrs. Silver returns home, she faithfully whispers the magic words in Alfie's ear, but does not notice that an exchange has been made.

Over the next 8 weeks, Mr. Hoppy continues to switch Mrs. Silver's current pet with a slightly larger tortoise, but she still does not perceive that her pet is growing in size. One afternoon, Mrs. Silver comments to Mr. Hoppy that Alfie seems a bit bigger but cannot tell for sure. Suddenly, Mrs. Silver notices that Alfie can no longer fit through the door to his house and exclaims to Mr. Hoppy that his spell is sure to be working. Mrs. Silver runs inside and weighs her pet and is surprised to find that Alfie now weighs 27 ounces (770 g), more than double the weight he was before. Mr. Hoppy summons his courage and asks Mrs. Silver if he can come down and see the effect for himself. Mrs. Silver, in raptures over her pet's transformation, gladly grants his request.

Mr. Hoppy runs down the stairs, nervous and excited to be on the brink of winning Mrs. Silver's love. Mrs. Silver flings open the door, embraces Mr. Hoppy, and expresses her admiration for Mr. Hoppy's magical spell. However, the tortoise cannot fit in the house now, so Mr. Hoppy tells Mrs. Silver to say the magic spell in reverse (Tortoise, tortoise, get bigger bigger, etc.). On the next night he secretly replaces this tortoise with one slightly smaller one. His part works splendidly, and Mr. Hoppy, suddenly emboldened by Mrs. Silver's warm smile, asks Mrs. Silver for her hand in marriage. Mrs. Silver delightedly accepts Mr. Hoppy's proposal, then adds that she thought he would never get around to asking. "All due to Alfie!" she cries.

Mr. Hoppy secretly returns all the tortoises in his living room back to their respective pet shops, telling all the owners that no refund is needed. Mr. Hoppy and Mrs. Silver are happily married a few weeks later. The "original" Alfie is bought by a girl called Roberta Squibb after he is returned to a pet shop; moreover, after many years, he does indeed grow to double his size before.

Despite Roald Dahl having enjoined his publishers not to "so much as change a single comma in one of my books", in February 2023 Puffin Books, a division of Penguin Books, announced it would be re-writing portions of many of Dahl's children's novels, changing the language to, in the publisher's words, "ensure that it can continue to be enjoyed by all today."^[6] The decision was met with sharp criticism from groups and public figures including authors Salman Rushdie^[7][8] and Christopher Paolini,^[9] British prime minister Rishi Sunak,^[7][8] Queen Camilla,^[7][10] Kemi Badenoch,^[11] PEN America,^[7][8] and Brian Cox.^[11] Dahl's publishers in the United States, France, and the Netherlands announced they had declined to incorporate the changes.^[7]

In Esio Trot, more than a dozen changes were made, including removing reference to Mrs Silver being "attractive", removing the word slave (changing "I'll be your slave for life" to "You'll be my hero for life" and similar), and removing reference to a woman changing her surname upon marriage.^[12][13]

The novel was turned into a BBC One television film of the same name. It features Dustin Hoffman, as Mr Hoppy and Judi Dench as Mrs Silver, with James Corden as the narrator.^[14] It was screened on 1 January 2015 and received praise, with The Guardian calling it "a thing of wonder".^[15]