High Quality Content by WIKIPEDIA articles! "420" is the twelfth episode of the seventh season of the animated comedy series Family Guy. It premiered on Fox in the United States on April 19, 2009. The title of the episode is a reference to the term "420" used in cannabis culture; "420" premiered the day before April 20 (4/20), on which a counterculture holiday is celebrated centering around the consumption of cannabis. "420" focuses on the character Brian after he is arrested for drug possession, which prompts him to launch a campaign to legalize cannabis with help from Stewie; the liveliness of their campaign convinces Mayor West to legalize the drug, and most of Quahog`s population begins using it.