this is actually based on a steven king short story/novel.

Did you read the story? It has almost nothing to do with the movie except for one small scene where a guy gets killed by a lawnmower.

The short story is about someone ordering someone to mow his lawn and a dirty fat ugly guy arrives. He goes to the lawn with this monstrosity of a lawnmower. The lawnmower proceeds to move on its own with an awful noise and the fat guy follows it around to eat up the cut grass. When the lawn owner sees this he is horrified and then gets killed by the lawnmower.