"Lobsterfest" is the twelfth episode in Season 1, being the twelfth episode overall.
A storm prompts the cancellation of the town's annual Lobsterfest, but Bob insists on opening his doors for a celebration anyway. Bob declares Bobsterfest and gives the townsfolk free beer and burgers. He wakes up to a trashed restaurant and angry Linda. Hugo is the grand marshal of Lobsterfest and Bob hooks him up with one of the Lobster Girls, Gretchen. Louise convinces Tina and Gene to go loot during the storm. They find a lobster walking on the street and decide to eat it, despite the fact the Bob (who is allergic to lobsters) had always taught them not to. The three are disappointed that their first time eating lobster is in the dark with toilet paper bibs. Tina thought her first time eating lobster would be at her marriage to Jimmy Jr., Gene during a concert (while dressed similar to Parliament Funkadelic's Bootsy Collins), and Louise as her last meal before getting the electric chair.
After eating the lobster, they discover that Gene is allergic to shellfish, and they go to Lobsterfest for the cure. Lobsterfest continues on the next day and the townsfolk couldn't care less about Bob's Burgers. Bob becomes angry and confronts the crowd. When the kids go to Lobsterfest, Bob sees them and notices something wrong with Gene, but doesn't remember what he looks like. He soon realizes Gene is allergic to lobster and blames Lobsterfest for this and threatens to put his big toe in the butter. One of the cops accidentally knocks Bob into the butter vat, contaminating all of the available butter in town and angering the townsfolk, who want to throw him in the shell pile. Ron convinces Hugo that he would not have his new girlfriend if not for Bob's help, so Hugo tests the butter and declares it safe for everyone but babies and people with compromised immune systems. However, Gretchen later breaks up with Hugo and he retaliates by springing a surprise inspection on the trashed restaurant.