Season 3: Episode 35: Lethal Weapons
Lois, tired of Peter treating her as if she doesn't exist, joins a Karate class. Finally acting on her emotions causes Lois to go berzerk. She fights off the "Leafers," the evil Kryptons, and she even defeats her Karate master. With so much testosterone flowing through her body, she becomes the man of the house...including in the bedroom. Meanwhile, Stewie takes a liking to the "new" Lois. He starts to see violence as an answer to all of his problems. Only until Stewie puts a bat upside the back of Peter's head does Lois realize her influence. She goes back to being herself...a mistreated mother and disrespected mother.