Gavin Nexdor is one of Gil and Susan's sons. He is the youngest brother of Nicholas and Thomas, the nephew of Johnny Test, Sissy Blakely, Jimmy Two Shoes, and Mary Test, the cousin of Kaitlyn Test and Samantha Two Shoes, and the grandson of Hugh Test and Lila Test. Like Thomas, he is considered a picky eater and will throw tantrums when he doesn't get his way.