Rebel

Rebel is a rottweiler dog who used to chase and scare Greg and Rowley when they were walking to school. According to Greg, Rebel's owner installed an electric fence so Rebel couldn't run loose. Greg and Rowley started to taunt Rebel, before Rebel discovered he would not be shocked if his collar didn't go over the electrical fence. Rowley was able to warn Greg about several of Rebel's "Land Mines", but Greg stepped on one of them when Rowley was not walking with him.