"Zannen na Ikimono Jiten" is a short-form anime series that humorously explores the quirks and peculiarities of various animals, presenting them in a comedic and educational format. Each episode focuses on a different creature, highlighting its unique traits, behaviors, and evolutionary oddities in a lighthearted manner. The narrative structure is episodic, with no overarching plot, allowing each segment to stand independently while maintaining a consistent tone of playful absurdity.

The main characters are anthropomorphic representations of the animals being discussed, often engaging in exaggerated and humorous situations to illustrate their characteristics. These characters break the fourth wall, directly addressing the audience to explain their traits or lament their perceived shortcomings. The humor arises from the contrast between the animals' real-world behaviors and the absurd, human-like dilemmas they face in the series. For example, a penguin might struggle with its inability to fly, or a sloth might comically overanalyze its slow movements.

The series blends factual information with comedic exaggeration, creating an entertaining yet informative experience. The animals' interactions and monologues often highlight evolutionary trade-offs or ecological roles, but these details are presented in a way that prioritizes humor over strict scientific accuracy. The tone is consistently light, with no serious conflict or dramatic tension, making it accessible to a wide audience.

Visual gags, rapid-fire jokes, and exaggerated character expressions are central to the storytelling, ensuring that each episode remains engaging despite its short runtime. The series does not delve into complex character development or narrative arcs, instead focusing on delivering quick, entertaining vignettes that celebrate the oddities of the natural world. By combining humor with a touch of education, "Zannen na Ikimono Jiten" offers a unique take on the animal documentary genre, appealing to viewers seeking both laughter and a casual appreciation for biodiversity.