If you enjoyed the Lemony Snicket: A Series of Unfortunate Events books or “The Addams Family,” the Edgar and Ellen series may interest you. Personally, I would have enjoyed these books very much as a kid; they have a creepy gothic sense of humor to them.
Edgar and Ellen are twins. Their parents left one day and never came back, and the twins have devoted their lives to playing pranks on each other and the people of their town. They live in a tall, dark, dilapidated mansion and spend most of their days playing hide and seek–which for Edgar and Ellen involves ropes, gags, and psychological torture.
Bored with hide-and-seek, they decide to earn money by stealing the pets of everyone in their town, disguising them as exotic animals, and selling them for thousands of dollars. But things don’t go exactly as they planned. . . .
There are six books in the series so far and more coming out soon. The intended audience is grades 3-4.