Glenn Quagmire (seasons 8-17)

Glenn Quagmire is a recurring character in the FOX adult animated comedy series Family Guy. He is the neighbor of the Griffins, who is known for crazing over sex 24/7.

While he was a tolerable character in the first seven seasons, sadly, he has been flanderized since the eighth season.

Bad Qualities

 * 1) He went from a kind of pervy ladies man, to a repulsive sexual predator who knowingly and gleefully shares his numerous STD's with the women he sleeps with (lying about wearing protection if he needs to), making him extremely unsympathetic to the audience despite how many times the show tries to give him sympathetic episodes (his sister being in an abusive relationship, him being tricked into marrying a prostitute, him being trapped in an abusive relationship with a "female Quagmire", etc.)
 * 2) The way he is written nowadays is all over the place, as he only likes women for their bodies rather than personality and he is not only a pervert, but also a child molester too.
 * 3) Sometimes, he is shown to be somewhat of a bad friend to Peter as he can be seen hitting on his wife Lois Griffin constantly.
 * 4) He abused Brian Griffin three times throughout the series; the first scene was when he severely beat up Brian Griffin, which is animal abuse, the second scene was when he broke Brian’s teeth with a lamp (although, the second time was justified since Brian scammed him into buying a run-down lot, despite that Quagmire helped Brian get his teeth repaired in the beginning.), and the third time is where he grabs Brian by the neck and bashes his head at the sprinkler, but after that, they soon apologized to each other, so thankfully it’s unlikely that they are ever gonna fight again.
 * 5) Speaking of which, he's a massive hypocrite in calling out Brian. It's implied that the real reason he hates Brian is that he's a dog, and Quagmire is a cat person. However, it was proven to be false because the true reason why he hates Brian isn't the fact that he's a dog. The true reason is that he doesn't like Brian's selfish personality. (Which to be fair, is understandable).
 * 6) Elaborating on Quagmire’s hypocrisy concerning Brian, Quagmire has not only done a lot of bad things Brian did, but the things done when Quagmire did them are a lot worse than when Brian did them. For example while Brian was revealed to have gathered only one kid and failed to treat him well, Quagmire on the other hand was revealed to have fathered more than six children yet he was never around for them.
 * 7) In “Quagmire's Baby,” he names his daughter after a sexual innuendo Anna Lee, and when he gives her up for adoption and sees she happy with her new family, it was a heartwarming way to end the episode, until its ruined when Quagmire said he could meet up with her when she's eighteen and have sex, which is incest.
 * 8) In "Quagmire & Meg," Quagmire plans to hump Meg when she turns 18, which is not just disgusting, but it also makes him a pedophile.
 * 9) In many episodes, he is just very easily offended. In “Wild Wild West”, he gets angry at Peter just for talking about someone that he doesn’t know, which is a very petty thing to do.

Good Qualities

 * 1) Despite hitting on Lois, Quagmire is very loyal to his best friend Peter as he would never try to hurt his feelings by stealing Lois from him.
 * 2) Although he developed a hatred against Brian, this was not the case during Seasons 1-7. But then the fans of hated on Brian, which may be the reason the writers decided to make Quagmire hate Brian, but in the recent episode "Cat Fight", he might have stopped hating Brian so it could be implied that he and Brian are on good terms now.
 * 3) He still cares about his family and friends. For instance, he defended Brenda from her abusive boyfriends Jeffrey. He also saved Brian and Meg from being kidnapped by cats in the episode "Family Cat"
 * 4) At least he didn't gloat over the death of Brian in the episode "Life of Brian".
 * 5) Despite not fully recovering himself from his flanderization, his character did see a slight improvement in season 18, mainly due to him being on better terms with Brian.

Trivia

 * His character spawned a lot of memes.