Luke Harrison's dad makes horror movies. It is a lot of fun being around a lot of such scary stuff - especially when you have your own monster museum at home. But when two ventriloquist dummies - Slappy and his twin Snappy - join the collection, things get real creepy. Slappy and Snappy can walk and talk on their own. And they can make you scream on their own. They have a plan to make everyone's lives miserable. Will Luke be able to stop this terrible twosome?
- This book was first announced by R.L. Stine during an interview, and later confirmed by Scholastic's website. 
- The title sounds similar to I Am Your Evil Twin.
- This is the third Living Dummy book to feature a second dummy as an ally to Slappy instead of an enemy.
- ↑ I Am Slappy's Evil Twin (Amazon) (mirror)
- ↑ SlappyWorld Interview: "I Am Slappy's Evil Twin"
- ↑ SlappyWorld Book #3 (Scholastic Website)
|Goosebumps SlappyWorld series|
|#01 Slappy Birthday to You|
|#02 Attack of the Jack|
|#03 I Am Slappy's Evil Twin|
|#04 Please Do Not Feed the Weirdo|