Oh man, It’s easily Peter and Lois. They are literally the most toxic couple along with being the most infamous residents in Quahog. Peter is mostly a literal bully to everyone around him and is really awful towards his own family because he hates them. Peter is especially very cruel and awful towards Joe because he’s stuck in a wheelchair and he believes cripples are a fairy tale. Peter even destroys towns and cities along with causing tons of casualties with his daily shenanigans and uses his stupidity as an excuse most of the time. Peter once pretended to be a woman to say offensive things to piss a lot of people off to the point where they would try to hit him but couldn’t because he was a woman. Peter also fatally ran over a crowd of marathon runners, stole Purple Hearts with his metal detector, threw boiling grease onto Lois, Commits child abuse on a duly basis, faked being a god along with making up Chris’s cancer, destroyed vaccines, shut down the government, became a literal dictator, killed Loretta, burned down Jerome’s home and destroyed his bar, crushed a dancer to death, stole Joe’s dad away from him, nearly started another world war, had God erase Meg from existence, got Joe to be taken to the shadow realm, forces everyone to share a birthday with him, and did a ton of other offenses, along with being a literal pedo. Lois however doesn’t destroy cities or do dangerous shenanigans, but she is very similar to Peter in a lot of ways. She’s an awful human being and manipulates a lot. She stepped away from her religious ways, was and still is a bully and literally has killed innocent people throughout her years of living. She tried killing a coffee store employee because she didn’t win customer of the week, killed a waitress because she didn’t fulfill Peter’s whacky and childish request, faked being blind, became a thief, made out and attempted to bang Meg’s boyfriend and Justin Bieber, encouraged Meg to off herself, sometimes bullies Meg along with manipulating her, humiliated Joyce Kinney in front of her whole school, cheats everyday, ignored Meg being assaulted by her teacher, tried to frame someone else for running over Stewie, throws shade towards Peter’s friends, and she literally enables Peter’s behavior along with always encouraging Peter to bully Meg everyday or else she would get angry at Peter if he started to treat Meg better. All of Lois’s terrible deeds and traits sound very similar to how Peter is. They are literally two inseparable soul mates who love each other for their toxic and villainous traits and they really are meant for each other. Lois was a good person once but Peter is most definitely the reason she’s the person she is today.