The Wonderful Demise of Benjamin Arnold Guppy, by Gina Collia-Suzuki.

Benjamin Arnold Guppy loved turnips. He loved eating them, but most of all he loved throwing them. He also loved money and pain... extorting a lot of the former and causing an equal amount of the latter. A foul, sour-faced old swindler with a penchant for clucking like a chicken and more than a passing interest in the local postman, he was determined to get his hands on his neighbours' money, regardless of the cost. As it turned out, the price was his life.

A tale of blackmail, turnip tossing, and the cold-blooded murder of an incredibly irritating old man.

Inspired by the author's experiences of living with nightmare neighbours from hell.