Since it first aired in 1999, Family Guy has brought laughs to viewers. The show centers on the Griffin family but over the 300-plus episodes in history, that family has interacted with characters that shape the overall course of the series.
The main characters were introduced to viewers during season 1, but many important and impactful characters were introduced afterward, especially since that season was so short. These characters changed the lives of the Griffin family while also creating memorable and wholesome moments on the show. In fact, some of these are among the most colorful and popular characters in series history.
Death
Death may not be the most conventional character to be introduced to the series, but fans recognize that he is hilarious each time he makes an appearance. Death was first introduced in season 2 after Peter attempts to fake his death in order to get out of paying a hospital bill. After that, Death comes knocking at his door and gets injured at the Griffin house, causing Peter to take over Death's job.
Death has become a favorite character for the Family Guy world because he not only reminds fans of morality, but he also brings a lighter view on death. Death is a relatable character that transformed the Griffin family for the better. He also has helped many Griffin family members recognize their value and their impact on the rest of the family.
Carter Pewterschmidt
Despite being Lois' father, Carter Pewterschmidt did not make his first appearance in the series until season 2. Carter Pewterschmidt is outspoken and cruel, specifically towards Peter, making him a hilarious addition to any episode he stars in. Carter is also extremely wealthy and often flaunts his money in order to get his way.
Carter is great mainly for the banter that occurs between him and Peter. Because he dislikes Peter so much, he takes any opportunity he can to humiliate him. However, there are many instances from the series where they help each other, making him a dynamic character that is consistently changing.
Mayor Adam West
Another major character that was introduced after season 1 was Mayor Adam West. Viewers were already familiar with the actor Adam West, and he does an excellent job at portraying himself as the mayor of Quahog. Mayor Adam West is a fun character that offers hilarious banter to the show while not being the brightest at times. Mayor Adam West also spends taxpayer money on useless things, causing turmoil for the residents of Quahog.
Mayor Adam West is an integral addition to the series because he brought more jokes and antics. Adam West's character also changed the series because of his inappropriate relationship with Meg in season 4, which later helped Meg to grow as a character.
Frank Sinatra Jr.
Despite being a recurring character in the series, Frank Sinatra Jr. has had a major impact on the show. He first appeared in season 4 where he helps Brian get out of his slump after having a near-death experience. Frank Sinatra Jr. also makes a few other appearances in which he opens various businesses with Brain and Stewie and having a friendship with them.
He is an important character because he is often helping Brian and Stewie to either overcome a major obstacle or being a friend to them. Frank Sinatra Jr. also impacted the show by performing six original songs, adding to the show's prominent song stylings.
Vinny
He may have only starred for a few episodes, but Vinny the dog was a crucial character to the Family Guy universe. Vinny was introduced in season 12 after the death of Brian as he was purchased by the Griffin family in order to fill the void. Despite Stewie being hesitant over Vinny's introduction to the family, he soon grows to appreciate him and they form a bond.
Vinny also became a close friend to Stewie and helped him with Brian's death. He was also important in helping Stewie travel back in time in order to reverse Brian's death, ultimately causing him to never be brought into the Griffin household.
Bertram
When he was first introduced in season 3, Bertram was the perfect personality match for Stewie. Stewie was originally trying to stop Lois and Peter from having another child by going into Peter's body to eliminate any potential offspring. After meeting Bertram, however, he is excited to have a little brother especially if it is going to be Bertram.
Even though Peter and Lois decide to not have more kids, Bertram is born into a different family. However, he becomes an enemy to Stewie after their initial meeting. Bertram was a consistent villain for Stewie to deal with until Stewie finally kills him in season 9.
John Herbert
John Herbert is first introduced to the series in season 3 and ends up being a recurring character moving forward. He is a neighbor of the Griffin family who develops an unhealthy obsession with Chris. John Herbert continues this fascination with Chris and is constantly fantasizing about a relationship with him.
Even though Herbert is inappropriate, he is still a major character introduced to the series. He has become an unofficial villain to Chris and continues to pursue him since his first appearance. His pursuit of Chris is always foiled, however, and he has stayed a minor character overall.
Jillian Russell-Wilcox
Jillian was first introduced in season 5 as a love interest of Brian. She and Brian have a relationship that lasts a few seasons, and their questionable dating is often judged by other members of the family. She is constantly calling and asking Brian ridiculous questions, which adds hilarity. After their breakup, she goes on to date other major figures in Quahog like Adam West and Quagmire.
Even though they break up, Brian makes multiple comments about his love for Jillian and how their relationship changed his life for the better. Jillian also develops a close relationship with Peter and Stewie, which has helped her stay a consistent character in the series.
James Woods
James Woods's first appearance is in season 4 and he develops an unlikely friendship with Peter. Unfortunately, he ends up having a falling out with Peter later on and they turn out to be enemies.
Even though he constantly causes havoc when he appears, James Woods is still a vital character to the Family Guy universe. He causes chaos for Peter and Brian on multiple occasions, but he also affects the lives of other prominent figures in Quahog like Tom Tucker and Diane Simmons.
Jerome
By far one of the most crucial characters to be introduced late is Jerome. He makes his first appearance in season 8 and becomes friends with Peter until he tells Peter about his former relationship with Lois. Peter becomes jealous and hates Jerome at first until he realizes that they have a lot in common.
Jerome stays a constant character after his first appearance. His daughter and Chris begin a relationship, despite Jerome having reservations about it. Jerome also becomes the owner of The Drunken Clam, a bar frequented by Peter and his friends, after accidentally killing the previous owner. Jerome has stayed a consistent character on Family Guy and has cemented himself in the future of the series.