Series 2: 201113 episodes
- Clive Warren
Karl tells Ricky and Stephen about his pitch of a movie starring "Clive Warren" and Rebecca De Mornay; Stephen reads more pages from Karl's diary, revealing Karl's dislike of camping in Australia and his tendency to save insects from falling into a swimming pool.
Karl discusses what his doppelganger would be like; Ricky gives Karl a riddle; what Karl does not like about Ricky's cat; Stephen discusses his holiday to Rio for Carnival.
- The Fly
The trio discuss animals and diseases; evolution; a fly that is kept as a pet; Karl's Diary.
Karl shares his thoughts on why insects are so deserving of his attention; disappointment learning about a killer octopus; what he would change in crabs; more stuff about insects; Karl's Diary also mostly about insects.
Karl tells the story of having kidney stones; Karl ponders a phenomenon; Karl's Diary; and more.
- Night Club
Karl ponders height extremes when he learns that one of his new fans is the actor Warwick Davis; Stephen tells the tale of him visiting a night club.
Karl makes several predictions about humanity's distant future.
- Natural History
Ricky talks about undiscovered species and shares an idea for the "Car of the Future".
- Leg Rubber
Karl discusses childhood memories of Tic Tacs, curing blindness with mice trials, and tells of his recent visit to a "professional leg rubber".
- Mrs. Battersby
Karl shares his thoughts about the two sides of the brain and the "sixth sense".
Karl discusses art and suggested adaptations of literature and film featuring The Muppets.
In the season finale, Ricky asks Karl if he would give up his real life to live in a virtual-reality isolation tank. And Karl discusses his thoughts about happiness. Karl finally laughs.
Ricky gives Karl some animal facts; Karl ponders the question of whether you control your brain, or does your brain control you. From Karl's diary we investigate the curious case of the invisible Chinaman.