The Former Life of Brian is episode 11 of family guy season 06. It was originally aired on April 27, 2008.
When Brian is afraid that he has lost his chance at love, he goes in search of a former flame Tracy only to discover he is the father of her unruly son, Dylan. After Brian’s surprise visit, Tracy drops Dylan off at the Griffin’s so Brian can raise him. Subsequently, his new little angel begins terrorizing the Griffin household and Brian’s self-important attitude toward parenting infuriates Peter and Lois.