How to kill a monster

Gretchen and Clark are staying with their grandparents, and they're not alone. They've got to kill the swamp monster who lives in a locked room upstairs before he eats them out of house and home. - from goodreads.

Main Author: Stine, R. L.
Format: Books Print Book
Language: English
Published: New York : Scholastic; 1996.
Series: Goosebumps ; 46.

Series: Goosebumps. Original series