What's a good prank to play on an annoying neighbor?
If they like their lawn you could infest it with dandelions. Just go out there every night and blow dandelion seeds all over it.
It's not really a prank, but you could steal their electricity.
Paint the house his least favorite color, bricks and all.
Egg their house!!!! LOL :P
Make them cookies....with onions inside of them. Small pieces of onions.
An annoying neighbor? Well when it's hot, put gummy bears on the roof and hood of their car:3