Must I Be a Crustacean in Love
Leela and Amy, dressed in workout clothes, find Fry and Bender slouching lazily on the couch watching television and drinking beer. The pair make disparaging remarks concerning Fry’s waistline and Bender's big beer belly. Leela announces she is taking Fry and Bender for a trip to the gym, and soon after, Dr. Zoidberg invites himself along.
At the gym, Zoidberg begins bench-pressing weights, pumping faster and faster until he clips the bar in two places with his claws. Zoidberg then charges through the gym in an insane rage, terrorizing others. Fry and the rest of the staff transport Zoidberg back to Planet Express, where they place thick rubber bands around his claws. Everyone is at a lose to explain Zoidberg’s manic behavior. The Professor examines him…and concludes it must be mating season for Zoidberg's kind. He tells the others that transporting Zoidberg back to his home planet is the only way to help.
The staff makes it way to Decapod 10, an ocean planet dotted with buildings resembling giant dribbled sandcastles. A Decapod Greeter welcomes Zoidberg and informs him it will be only nineteen more hours before the mating frenzy begins. Leela, Fry and Bender accompany Zoidberg to the beach, where Zoidberg attempts to attract a mate. Unfortunately, the females do not respond to his mating call, and eventually, Zoidberg looks defeated.
Things begin looking up when Zoidberg spies a high school friend named Edna. But she, like the other females, rejects Zoidberg’s advances, abeling him an "inferior male specimen." Zoidberg’s spirits sink. Later, Fry tells Zoidberg that if he wishes to mate, he must learn how to fake being in love. As Fry prompts him from a hiding place, Zoidberg tells Edna everything she wants to hear…and Edna’s attitude towards him softens. Fry’s tutoring lands Zoidberg a date with Edna at a restaurant. But during the meal, Zoidberg utters a typically insensitive remark.
Leela approaches Edna in the ladies' room and tells her not to pay any attention to Zoidberg, as Fry has been coaching him what to say. Later, Fry drops by Edna’s apartment to sing Zoidberg’s praises and assure her he is a really a nice guy. But Edna is now enamoured of Fry, as it was his words she fell in love with. Edna grasps Fry in a powerful embrace and kisses him.
At that moment, Zoidberg enters and catches the pair in the act. Fry assures Zoidberg that he has no romantic feelings for Edna. But Edna claims this is untrue, and, according to her, the two plan to mate the following day. An angered Zoidberg challenges Fry to Klaw Plach—a fight to the death. Fry is placed in shackles and thrown before a Decapodian priest, who announces that the pair shall fight to the death for the right to make love to Edna. Fry insists he has no interest in her, but the priest tells him that once Klaw Plach is invoked, It cannot be recanted.
As the mating time reaches its fever pitch, Fry chooses a huge nutcracker as a weapon and uses it to defend himself. As the battle rages, Fry manages to grasp a helpless Zoidberg in the device. The Decapodian crowd urges him to kill, but Fry raises the nutcracker and hurls it away. Fry tells the crowd that a violent act would be meaningless. He also assures them that he and Zoidberg are friends and will always remain so.
Suddenly, Zoidberg snips off one of his arms. An outraged Fry picks up his arm and begins beating Zoidberg with it. Leela tells the pair to stop fighting, as everyone in the stadium has disappeared. Fry, Bender, Leela and Zoidberg run to a promontory and look out over the beach. They see many Decapodian couples mating in the water, including Edna and the priest, who are claw-in-claw. Zoidberg laments having missed the opportunity, but points out that once his species passes its genes, it dies.
Later, Zoidberg reattaches Fry’s arm using a laser instrument. Unfortunately, he attaches it to the wrong shoulder.