Dylan Flannigan is the son of Brian Griffin and Tracy Flannigan, and one of the 4 main protagonists of Advanced Education the Movie: Strong Forces.
Dylan is a tall and slender teenage boy with fair skin, blue eyes, and blonde hair. He had a mullet in his debut, and his hair was messier, but when Brian changed him, his hair got neater, and his mullet was shaved off.
When he first appeared in "The Former Life of Brian", Dylan had a mullet and wore a maroon t-shirt with a white skull on it, a black vest, black studded arm-bands, dark green baggy cargo pants with a chain attached on the left side, and black converse sneakers.
After Brian helped Dylan change his behavior, Dylan was seen wearing a brand-new outfit, consisting of a blue short-sleeved polo shirt with a white undershirt, khaki pants, and the same sneakers.
When he returned in "Brian's a Bad Father", Dylan wore a maroon short-sleeved polo shirt with a darker border and dark blue and light gray stripes, blue jeans, and the same sneakers.
His outfit for when he is acting in "Parent Boppers" consists of a blue t-shirt with a yellow lightning bolt on it underneath a white blazer with rolled-up sleeves, gray skinny jeans, and blue sneakers with black soles and light gray laces.
In Advanced Education the Movie: Strong Forces, Dylan wears yet another new set of attire, which consists of a green Riddle School t-shirt with a dark green border and Phil Eggtree's face on it, a maroon sleeveless hooded jacket with light gray trim and a dark blue hood and zig-zag stripes on the middle, a darker maroon stripe in between the blue stripes, and chest pockets with gray on the flaps. He also wears blue fingerless gloves with gold plates and studded borders, blue cargo pants, and his black converse sneakers.
Brian left Tracy before Dylan was born, leaving him not knowing what it's like to have a father. When he visits Tracy, she had become a fat slob. Tracy told Brian and Stewie about Dylan when they went to visit her. Brian goes back to the house and tells Peter and Lois about him. Tracy soon drops Dylan off at Brian's so father and son could bond. At first, he was disrespectful towards Brian and his family. When he is introduced to Chris, the Evil Monkey comes out of the closet, only to have Dylan brutally beat him. When Brian decided he was finally going to give up, one of them dropped a bag of pot. They both called out for it. While smoking the pot they realized they had a lot in common and became close. Brian soon became very protective of Dylan.
Brian was very tired of Dylan's bad attitude, so he turned him into a nicer person. Peter, sick of Brian's overemotional reactions to the slightest things, convinced Tracy to take Dylan back. Even though Brian was against it, Dylan said he must go because he can change his mom's life the same way Brian changed his.
Glenn Quagmire pointed out to Brian during his rant in "Jerome Is the New Black" that he is not a part of his son's life.
Dylan returns in "Brian's a Bad Father" as a star in a new Disney Channel show Parent Boppers. Although Brian is at first reluctant to visit with him, when he discovers Dylan has achieved television success, he quickly rushes to Dylan and asks him to use his contacts to help him secure a gig as a writer on the show. However, Brian soon alienates the other members of the production team and encourages the young stars to alter their own dialog in an overly-dramatic fashion. Brian is fired from the show and his begging for Dylan to intervene makes him realize that Brian only cares about his connections, rather than himself. When Brian finally realizes what he has done, and tries to apologize, he finds himself barred from the studio. Stewie comes to his aid by dressing up as super-cool teen Zac Sawyer, and after landing a place on the show, delivers a message of parental love and Dylan and Brian reconcile.
Stewie mentions Brian's abandonment of Dylan in "Quagmire's Mom" and Stewie alludes to Brian's poor parenting in "Stewie Is Enceinte", offering him a second chance at fatherhood.
Peter brings up that Brian's son was an actor in "The Peanut Butter Kid" and attends Brian's wedding in "Married...With Cancer".
Dylan has a major role in Advanced Education The Movie: Strong Forces, as one of the main protagonists. He is first seen in the Principal’s Office, as he is being lectured by the principal and his mother for vaping in the locker room. They then suggest that he spends a week with his father in order to get his life and behavior back on track. He shows up at the Griffin House shortly after Stewie and Brian’s first encounter with the Galactic Federation. Dylan reconnects with his father, and later meets Caillou, along with the rest of his friends as they all go to the Stadium Theatre together to see Sister’s Act, but they had to leave early, due to Aunt Sally’s sickness. Dylan then goes with Stewie and Brian to spend a weekend with Tom and co. in Milford, where they hear about the Galactic Federation from Tord. He then joins the gang during a day out with Gammy, and escapes from the Griffin house with Rick’s group, as it was overrun with agents from the Galactic Frontier. He then works with the gang to save their friends and put a stop to the Galactic Frontier.