First person: I (formal/military) Gender: Male Species: Penguin Height: Second shortest among the Penguins He serves as the leader, giving operation names to missions and precise instructions to his teammates. He has a personality like a stereotypical soldier with a love for dark humor. Described by Kowalski as having a "personality disorder," he is suspicious and prone to making wild deductions based on extreme paranoia. He tends to look down slightly on non-bird animals and displays some old-fashioned attitudes. However, as a leader, he possesses high command and combat abilities (capable of taking on his three subordinates alone, and once knocked out a walrus with a single blow). He is deeply loved by his subordinates because he spares no effort to fulfill their wishes, and even his enemies occasionally show him affection. Everyone calls him Skipper or Boss.

First person: I (formal/polite) Gender: Male Species: Penguin Height: Tallest among the Penguins Speech style: Polite/Honorifics He always carries a clipboard and pen, instantly analyzing the situation. He owns a scratch-and-sniff animal encyclopedia. While confident in his intelligence, he is poor at reading text; consequently, his plans and reports consist mostly of drawings. When his brain or body takes damage, he may make very childish remarks. He usually speaks calmly, but his voice cracks when he gets excited. He is also surprisingly prone to tears. A science fanatic who gets abnormally excited about research, he is a mad scientist who sometimes puts his teammates in danger. Experiments and inventions are his life's work, but his inventions often cause trouble, leading Skipper to ban him from inventing at times. He believes the power of science is absolute and feels frustrated that Skipper and the others don't understand chemistry.

First person: I (soft/polite) Gender: Male Species: Penguin Height: Shortest among the four He has a very gentle and kind personality, and his main selling point is his cuteness. However, his combat skills are high, such as dodging Skipper's attacks while blindfolded. He is well-spoken but, due to his immaturity, sometimes exposes the base's secrets to others. Although timid, he occasionally performs physically demanding missions. He loves peanut butter chocolate bars and is afraid of badgers. He often ends his sentences with a polite "sir" or "-ssu" equivalent. He has a habit of shouting "Chest!" when taking action. Due to his natural cuteness, he once graced the cover of the zoo brochure, lost the spot to another animal for a while, but later returned to the cover. He believes in magic. Lacking the ruthlessness of a soldier, he sometimes trusts animals who are clearly villains or tries to find solutions other than attacking, for which Skipper scolds him.

First person: Rico (rarely I [rough]) Gender: Male Species: Penguin Height: Second tallest (shorter than Kowalski) Catchphrases include "Kaboom!", "Fish!", and "Ka-bra-vo!" He can store weapons and other items in his bottomless stomach, regurgitating various tools ranging from musical instruments to machinery and howitzers upon request. Skipper calls him a "world-class eccentric." He loves explosives like bombs and bazookas and wants to destroy everything immediately, which has been exploited by others. It is also his job to destroy Kowalski's failed inventions. When his destructive behavior goes too far, he turns into a living weapon and becomes uncontrollable. Skipper generally views this craziness as an asset and gives instructions to utilize it in appropriate places; Rico is highly loyal to Skipper and follows him well. He cannot speak clearly and has a raspy voice.