Jonathan Chiller is the main antagonist of the Goosebumps Horrorland Books after The Menace in books 13-19.
Jonathan had a troublesome and lonely childhood that his mother thinks he has a special brain. This made Jonathan incredibly smart and a skilled hunter. He desires friends and uses the monsters for this cause.
Throughout the books he had been using the monster to attack the protagonists. It's later revealed that he disguised himself as the monsters that attack the protagonist.
He is appears in throughout the book provide items to the protagonists and disguising himself as most of the monsters having been hired to be the owner of the shopkeeper by the Horrors for Horrorland.
He was eventually defeated by the protagonists disguising as his friends and forced to let them go.
