«Diary of a Dog Owner» by Jeff Child

A witch, a smart guy, an evil monster, and a courageous dog.
In this diary of a regular guy, you'll find an adventure that starts with a murder scene, unfolds into a mysterious search, and ends with the defeat of evil. Cedric is an average citizen of his little town, but when his name appears on a creepy wall with previous victims, he knows he has to do something, or he will be next. His dog, Bruno, and he pursue a suspect and are shocked at what they find.