"Goosebumps 2: Haunted Halloween" is an American horror comedy film directed by Ari Sandel and written by Rob Lieber. It is based on the children's book series of the same name by R. L. Stine and a sequel to the 2015 film Goosebumps. The film stars Wendi McLendon-Covey, Madison Iseman, Jeremy Ray Taylor, Caleel Harris, Chris Parnell, and Ken Jeong.
Teenager Sarah Quinn (Madison Iseman) lives with her mother Kathy (Wendi McLendon-Covey) and younger brother Sonny (Jeremy Ray Taylor) in Wardenclyffe, New York. Sarah is attempting to get into Columbia University by writing an essay about fear. Kathy agrees to watch Sonny’s friend Sam Carter (Caleel Harris) while his father goes out of town.
Sonny and Sam are attempting to start a garbage cleanup business, and are called after school to clean up an abandoned house. Inside, they find a locked manuscript and open it, causing Slappy the Dummy to appear. They unknowingly bring him to life by speaking magic words found in his pocket. The manuscript is later stolen by a bully named Tommy Madigan (Payton Wich).
At home, Sonny is working on his science project, a miniature version of Nikola Tesla’s Wardenclyffe Tower. Slappy then reveals he's alive to Sonny and Sam, and gets their trust by using his magic to do the boy's chores and homework. Meanwhile, Sarah goes to a party to meet her boyfriend Tyler (Bryce Cass), but sees him kissing another girl. Slappy sabotages Sonny's science project and overhears Sarah talking about Tyler.
The following day on Halloween, Slappy uses his powers to attack Tyler, and Sonny accidentally damages the school science lab with his sabotaged science project. Later, Sarah arrives home and questions two boys about Slappy. The group realizes that Slappy is at fault and is evil. The kids capture Slappy and try to dispose of him, but he escapes. Later that night, they find an article online about the events that happened in Madison, Delaware and try to contact R. L. Stine (Jack Black) after realizing the book they found was an unpublished Goosebumps manuscript called Haunted Halloween. Stine, now living in a cabin in the woods, hears their message and departs for Wardenclyffe.
Slappy goes to a local drug store, and uses his magic to bring Halloween costumes and decorations to life. He also transforms an employee named Walter (Chris Parnell) into a hunchbacked ogre. He then travels to the Tesla tower, using it to channel his magic.
Sarah, Sonny and Sam retrieve the book from Tommy’s house while all the town’s Halloween decorations come to life. They soon discover that the book can trap the monsters inside. However, the book is stolen and Kathy is kidnapped by the monsters.
The kids’ neighbor Mr. Chu (Ken Jeong), a Goosebumps fan who is thrilled to be trapped in a living Goosebumps story, helps them craft monster disguises to safely navigate the town. The kids head for the Wardenclyffe tower while Stine arrives in town.
At the tower, the kids encounter Slappy and Walter and discover that Slappy has turned Kathy into a living dummy. Sonny and Sam overload the reactor while Sarah fights Slappy. She defeats Slappy by kicking him into the electrified coil atop the tower, which blasts him into the sky. Sarah opens the book, combining it with the reactor's energy to suck all the other monsters into the Haunted Halloween manuscript. Kathy and Walter return to normal. Stine arrives and congratulates the kids for defeating the monsters, as well as offering Sarah writing advice for her essay.
Sometime later, Kathy and Walter start dating, Sonny wins the science fair and Sarah gets an email saying she got into Columbia University. Back in Stine's cabin, he finishes a new book. Slappy appears, revealing to have survived and wrote a book of his own where Stine is the main character. He then opens the manuscript, sucking Stine inside.
- Jeremy Ray Taylor as Sonny Quinn
- Madison Iseman as Sarah Quinn
- Caleel Harris as Sam Carter
- Wendi McLendon-Covey as Kathy Quinn
- Chris Parnell as Walter
- Ken Jeong as Mr. Chu
- Avery Lee Jones as the voice of Slappy the Dummy from Night of the Living Dummy. He was previously voiced by Jack Black in the first film where Jones performed Slappy.
- Jack Black as R.L. Stine, the creator of the Goosebumps books and the monsters who reside within them.