Season 6: Episode 132: The Day the Spores Landed
Cliff dreams that the eruption of a volcano in Peru has sent spores into the drinking water and caused men to become pregnant. Cliff, Elvin, Martin and Theo are all pregnant. Theo deals with stares and unkind comments because he is an "unwed father." The pregnant men all become very emotional, while the women act insensitive toward them most of the time. The guys all go into labor at the same time, and suffer excruciating pain. Martin gives birth to a toy sailboat, while Theo has a mini sports car. Cliff has twins: a gigantic hoagie and a bottle of orange soda. After "experiencing" pregnancy and childbirth, Cliff wakes up and tells Clair how much he appreciates her and how much he admires all women.