"I Shrink Therefore I Am." Season 4, episode 8.
Sometimes I love Farscape's love of punning episode titles. "The Way We Weren't," "Bringing Home the Beacon," and "Throne for a Loss" are all clever titles. But I feel like they got a bit carried away with it in the fourth season. That all three parts of the "We're So Screwed" trilogy have punny titles is just exhausting.
Similar with the weird animal thing going on at the end of the third season - "Into the Lion's Den," "Lambs to the Slaughter," "Wolf in Sheep's Clothing," "Dog With Two Bones." Although that works a lot better.