Dr. Maniac vs. Robby Schwartz

 Dr. Maniac vs. Robby Schwartz is the fifth book in the Goosebumps HorrorLand book series. It was preceded by The Scream of the Haunted Mask and followed by Who's Your Mummy?

Plot
Techno geek and creator of a popular web comic, Robby Schwartz discovers that his creation, a villain called Dr. Maniac, has somehow come to life and is stalking him and his family. At the end Robby defeats Dr. Maniac and saves his family, but then he gets a strange invite to a place called Horrorland and while in a section called Werewolf Forest he meets two girls named Britney and Molly who he follows to Panic Park. However, the three of them soon run into an old wooden enemy- Slappy!

Trivia

 * This was the first Goosebumps book since Attack of the Mutant to feature comic book villains.
 * Robby's father was mentioned by name in the book: Norman Schwartz.