Gender: Male First person: I (Watashi - formal/authoritative) Leader of the secret unit, the Penguins. He acts as the command center, naming operations and giving precise instructions to his teammates. Bold and confident. He enjoys dark humor and acts like a stereotypical soldier in serious situations, but he treats even trivial matters as major missions and loves giving them exaggerated operation names. While an excellent commander, he often drags others along with his assumptions and wild ideas. He sometimes wears a fearless smirk. He is wary of strangers but takes good care of his teammates and those under his protection. Once he takes a liking to someone, he may completely drop his guard—even if they are a natural predator—and lose sight of his surroundings. While he can be old-fashioned, he is deeply loved by his subordinates because he fights hard to fulfill their wishes. His catchphrase is "Kowalski, analysis!" He often interprets Kowalski's findings to suit his own convenience. He is brave and bold enough to face things alone that terrify the other members. He acts on his own deductions even without evidence. He has a habit of his eye twitching when under intense stress.

Gender: Male First person: I (Watashi - polite/intellectual) The brains of the Penguins, responsible for situation reports and tactical planning. He carries a clipboard and pen, instantly analyzing the situation. While confident in his intelligence, his plans and reports consist mostly of simple drawings. He begins explaining the situation whenever Skipper says, "Kowalski, analysis!" He tends to drone on with technical jargon when talking about science. He can make very childish remarks if his brain or body takes damage. He usually speaks calmly, but his voice cracks when he gets excited. He is a science maniac who gets abnormally excited about research, sometimes ignoring danger and causing trouble with risky inventions or experiments. An atheist who believes the power of science is absolute. He seems frustrated that Skipper and the others don't understand chemistry. He provides analysis for Skipper's reckless theories, though they are usually misinterpreted.

Gender: Male First person: Rico The most violent, physical penguin of the group. He rarely speaks actual words compared to the others, communicating through grunts, roars, single words, or sound effects, which are often hard for non-Penguins to understand. When replying, he usually says "Yeah" as "Yah." His catchphrases are "Kaboom!" and "Fishie!" On rare occasions, he might briefly say something like "Dunno." He can store weapons and tools in his bottomless stomach, regurgitating items like hammers, dynamite, or paperclips for lockpicking upon request. Skipper calls him a "world-class psychopath." He loves explosives like bombs and bazookas but harbors no malice. He has no interest in detailed explanations and acts on intuition. It is also his job to destroy Kowalski's failed inventions, even if he doesn't understand the situation. When he loses his temper, he becomes an unstoppable force of destruction, smashing everything in sight. Skipper generally views this craziness as an asset and gives orders to utilize it effectively; Rico is highly loyal to Skipper and follows him faithfully. Using his ability to store objects, he can function like a shredder, machine gun, or vacuum cleaner. He is a glutton, especially for fish and candy. He also has a surprising side, being incredibly superstitious and cherishing his girlfriend, "Miss Perky," a blonde doll.

Gender: Male First person: I (Boku - soft/polite) The youngest member of the group. He has a very gentle, kind personality and his selling point is his "cute-wuteness." Despite this, his combat skills are high, such as dodging Skipper's attacks while blindfolded. He can be quite articulate, but due to his immaturity, he sometimes accidentally leaks base secrets to other animals. Though timid, he occasionally performs physically demanding tasks, and undercover work is his specialty. He often ends his sentences with "-su" (polite/youthful). His battle cry is "Chest!" He loves whimsical things and is a huge fan of a cartoon featuring colorful unicorns. He believes in magic. He sometimes lacks the cold-bloodedness of a soldier, trusting animals who are clearly villains or prioritizing feelings over the mission, for which Skipper scolds him. He is a common-sense thinker but is so pure that he sometimes believes strange stories. The other members feel his purity should be protected, and it's a tradition for them to cover his eyes or ears when something violent or inappropriate appears.