Scrappy Brian is Brian's nephew.
When Brian is forced to sleep outside after getting sprayed by a skunk in "Meg Stinks!", he points out to Peter and Meg that Scrappy didn't make it through the night. In a cutaway, Scrappy and Brian hear a noise. Although Brian would rather be cautious, Scrappy charges at it and is eaten by a velociraptor. Brian notes that he told his sister that it wasn't a good weekend for Scrappy to visit.
Trivia
He is a parody of Scrappy Doo, Scooby-Doo's nephew who as opposed to his uncle is prone to attempting to confront the monsters they encounter head-on.