TV-Series
Description
Pen-Pen is a warm-water penguin who lives with Misato Katsuragi in the anime series Neon Genesis Evangelion. He is her companion and pet, though she regards him as more than an ordinary animal. Pen-Pen resides in a specially modified second refrigerator in Misato's apartment, which is fitted with a bed, a lamp, and other comforts suited to his needs.

In terms of background, Pen-Pen is a genetically altered penguin with no exact real-world counterpart. He most closely resembles an erect-crested penguin in appearance, but he is adapted to warm water and possesses retractable claws, three on each flipper, a feature that no living bird species has. His enhanced intelligence and unusual traits suggest that he was created through advanced genetic experimentation. The manga adaptation offers a more detailed explanation: Pen-Pen was produced as a test animal at a research laboratory where Misato once worked, and when the experiment concluded, she adopted him to save him from being euthanized. He wears a collar bearing the serial number BX 293A and a small backpack whose function is never explained in the story. He is capable of removing and putting on the backpack himself.

Pen-Pen's personality is calm, relaxed, and curious. He spends much of his time napping, eating, and enjoying warm baths, and he is often shown taking part in human activities such as watching television, reading newspapers, eating human food, and drinking beer, with Yebisu being his preferred brand, the same one Misato drinks. His behavior suggests a near-human understanding of the events unfolding around him, and he responds to the emotional states of the people in his household with noticeable sensitivity. His motivations are simple: he seeks comfort, food, warmth, and affection, and he serves as a dependable source of companionship for Misato, who carries heavy professional and personal burdens.

In the story, Pen-Pen functions primarily as comic relief, providing a light and uncomplicated presence in a setting otherwise marked by tension and psychological strain. He shares Misato's apartment with Shinji Ikari and later with Asuka Langley Soryu, and his relaxed habits often create humorous situations, including startling both of them in separate bathroom encounters. He also acts as an emotional anchor for the household, offering quiet stability and warmth when the human characters struggle. When a devastating attack leaves much of the city unsafe, Misato sends Pen-Pen away to stay with Hikari Horaki's family to keep him out of danger, a moment that reflects her deep attachment to him. In the Rebuild films, Pen-Pen retains a similar role, appearing in comic scenes and remaining a familiar presence during major events. In the final film, many hot-spring penguins appear at the preserved ruins of NERV-02, suggesting that the species has multiplied, though it is not clear whether Pen-Pen himself is among them.

Pen-Pen does not undergo significant character development in a traditional sense; his value to the story lies in his constancy. His notable abilities include his enhanced intelligence, his retractable claws, his capacity for expressive gestures, and his unusual warmth-tolerant biology. He has no combat abilities and does not take part in the battles that dominate the series, but his presence remains significant to the characters around him.
Cast