This is not going to end well. I'm guessing he and wifey aren't coming over for dinner anytime soon?
Here's some ideas for ongoing shenanigans that will have your neighbor thinking twice about his recent purchase...
1. Next time you mow the lawn, wear a KKK outfit
2. Hang a big pentagram on your front door
3. When you go to get your morning paper, do so in a pair of Speedo's that are 2 sizes too small
4. Wear a turbin with the Speedo's
5. Get a pet crocodile and keep it chained up on the front porch
6. Post up a couple signs on the closest telephone poles explaining of how a half dozen king cobras got loose from your property (don't forget to offer a reward for return)
7. Sneak a big DUB sticker on the back of his GTO