Nanny McPhee and Diamond are two horses that Roger "borrows" to hitch to his carriage in order to take Stan and Francine to a horse show in "Adventures in Hayleysitting". When Roger destroys the carriage on the highway by racing cars, he places Stan and Francine on the horses in order to get them to their show but the horses instead head back to their stable. As Stan and Francine regret not getting to see the show, the other horses in the barn perform for Stan and Francine as they make love, with Nanny McPhee and Diamond joining in.