The cover illustration depicts Slappy sitting on a old, broken chair with his son, a miniature version of himself.
Jackson Stander is every parent's dream. He doesn't get into trouble, he always does his homework, and he never ever lies. His teachers all trust him completely. He even volunteers at the local Youth Center. But that was all before Jackson came across an evil ventriloquist dummy. Now he must deal with Slappy wreaking havoc on his family and friends. Jackson will soon see that two Slappys are not better than one!
Jackson Stander is a tweenage boy who tries his level best to behave as well as possible. His bratty sister Rachel calls him a "goodie-goodie" for this, and hates that their parents and teacher constantly want her to be more like her brother. She keeps trying to get him in trouble, but it always fails.
Jackson volunteers and looks over the kids at the town's Youth Center, which they call the YC. One day, Mom announces that the kids will be visiting their maternal grandfather over spring break. Rachel hates him due to his creepy house and collections of weird stuff, while Jackson really likes him and finds his collections awesome. Soon after they arrive, Grandpa Whitman shows them his latest collection, which is of ventriloquist dummies. One of his dummies is Slappy, but Whitman claims the real Slappy was destroyed long ago and this is only a copy. He has called the copy "Son of Slappy". Grandpa's creepy manservant Edgar still thinks he's evil but Whitman says he's just superstitious.
A few days later, it's time to leave but when they get home Jackson discovers that Son of Slappy in his suitcase. He assumes Edgar did it to get rid of him. Jackson finds some strange words on a piece of paper in Son of Slappy's pocket but he stops before reading all the words. His friends Mickey and Miles drop by, and after they mock him, Jackson decides to mess with them by claiming he has the real Slappy.
After Rachel comes in and reads the words out loud, Jackson thinks he sees Son of Slappy wink but he assumes he just imagined it. At the YC, the director Mrs. Pearson tells him that the YC is running out of money, and that they need Jackson's help with things like a bake sale so that they can raise the funds needed to stay in business. Jackson agrees to come up with an idea to spice up the bake sale.
When he gets home, Son of Slappy comes to life and reveals that he is actually the real Slappy, and the Son of Slappy stuff was just a story Whitman heard. However, Slappy says there is a Son of Slappy: Jackson. Jackson hears a loud chirp, and then he finds himself laughing evilly along with Slappy. The next morning, he assumes it was all just a bad dream.
During art at the YC, Jackson hears the chirp again and finds himself trashing the art room, all while Slappy is cackling in his ear. When the kids come in, he tells them that three dogs came in and trashed the room. During school, Jackson hears the chirp and then takes the answers to an upcoming history test. His teacher Mrs. Hathaway notices it went missing and when Jackson thinks about how he'll get an easy A, he finds himself cackling out loud.
When he gets home, Jackson tries to get rid of Slappy but before he can, he hears the chirp. Then Aunt Ada, Uncle Josh, and Cousin Noah come over for dinner, and Jackson starts insulting everyone. Jackson is sent to his room and he tries to prove to Rachel that Slappy is really alive, but Slappy doesn't do anything. He then hears the chirp and starts insulting her, causing Rachel to run out to tell on him. Slappy then starts choking Jackson as punishment for telling on him.
The next morning, Jackson tries to tell Mom the truth when he hears the chirp and then starts insulting her. He also dumps cereal on Rachel and pours honey on his sweater, claiming that she did it. Due to his current behavior, Mom doesn't believe him and grounds him. During the following week, Slappy doesn't make him do anything so he starts to seem calm enough for his parents to let him go back to the YC.
On his way to Mickey’s house, Jackson sees a small boy whose bike has gotten stuck in the mud. But before he can help him, he hears the chirp and throws the bike into the street. At Mickey’s house, they start making a batch of cupcakes. But after hearing the chirp, Jackson ruins them. Mickey’s mom sees this and tells Jackson's folks, who ground him from going go the YC's bake sale and talent show.
On the night of the show, he plans to sneak out as he has figured out how to stop Slappy. He figures out the chirp is coming from the Chirping Chickens game on his game player that he carries everywhere, so leaving it home will stop Slappy from controlling him. He takes Slappy to the YC to do a ventriloquist act, but during the act, he hears the chirp. This time it's coming from a canary that they keep at the YC. Slappy starts making rude jokes and then bites a kid's hand. In the chaos, Jackson tries to find the magic words, figuring they would put him back to sleep but it has been replaced by a blank page.
A few weeks later, Slappy's actions have ruined Jackson's life as everyone thinks he went bad, and he is grounded for the rest of the school year, and banned from the YC. They also refuse to let him throw away Slappy, as he belongs to Grandpa Whitman, although he does lock him in a suitcase in the basement.
One night, Jackson hears Rachel talking to someone in her room. He looks and sees that she is talking to Slappy. She reveals that she brought Slappy to life on purpose after hearing about him so she can get revenge on Jackson for always making her look bad. She also hid the words so Jackson couldn't put Slappy back to sleep. Slappy thanks her for being a good daughter of Slappy. They tell Jackson they know he's listening to them, and then he hears a loud chirp.
|No.||Book||Country/Language||Translated title||Release date|
O Filho Mais Procurado
|The Most Wanted Son||2014||Fundamento|
Son of Slappy
|Son of Slappy||July 6, 2017||Scholastic|
Le Fils De Slappy
|The Son of Slappy||September 27, 2017||Bayard Poche|
- This book shares similar plot elements with the Goosebumps Series 2000 book Horrors of the Black Ring. Both stories feature abnormally well behaved protagonists who are controlled by the antagonist and forced to do evil things.
- This is the final book to use Slappy's HorrorLand redesign (minus the classic reprints). All the following books featuring Slappy depict him as he appeared in the Goosebumps movies.
- This book makes references to Godzilla, Nerf, iPod, Bugs Bunny, Piggly Wiggly, the Sly & The Family Stone song "Dance to the Music", Frosted Flakes, Cheerios, and the Guinness Book of World Records.
- Additionally, the game Chirping Chickens is a parody of Angry Birds.
- Mrs. Stander's age is revealed in the book to be 36.
- Mrs. Stander's maiden name is also revealed to be Whitman.
- In France, this is the first book in the Living Dummy saga where Slappy is referred to by his actual name. In previous books, he was referred to as 'Clic-Clac', 'Diabolo' and 'M. Méchant-Garçon'.