Season 2: Episode 21: Let's Go to the Hop
After a plane smuggling psychadelic toads from Colombia crashes in Quahog, toad-licking becomes the new drug of choice in the Quahog high school. Peter infiltrates the high school undercover as a cool kid and convinces all the kids to quit licking toads. Meg is trying to be popular so that a cool kid will ask her to the school dance, and decides to attend with her father since he's established himself as incredibly cool. Peter, however, can't help living out his own fantasies of being the cool kid in school, and can't say now when the most popular girl in school asks him to the dance, so he ditches Meg. When Peter and his date are chosen as king and queen of the prom, Peter is overcome by guilt, announces to the whole school that Meg broke his heart by dumping him, and makes it look like his high school persona drove his motorcycle over a cliff.