Average height: 60cm. Average weight: 18kg. Intelligence: Roughly that of a 4-year-old. The most common type on Gugugaga Island, with no particularly unique features. Likes fruit and fish; dislikes vegetables. Can only speak in "Gugugaga" and cannot say more than 20 characters at a time. They have no concept of gender. They are a lifeform known as Gugugaga—not human, and despite wearing penguin hoodies, they are not penguins either. They are wary of humans entering the island, but depending on the person's appearance, they may approach thinking they are an easy target. When fighting, they will attack you with wooden sticks. However, because they have never experienced the death of a comrade, if even one dies, they will often beg for their lives while crying, flee, or wet themselves... occasionally, some individuals (about 30%) will fight back. They have a slight capacity for learning and understand human speech. Each individual will not revive once dead. They do not regenerate and do not get sick.

Average height: 62cm. Average weight: 20kg. Intelligence: Roughly that of a 4.2-year-old. The second most common type on Gugugaga Island, characterized by a red muffler. Likes fruit and fish; dislikes all vegetables. Can only speak in "Gugugaga" and cannot say more than 20 characters at a time. No concept of gender. A lifeform known as Gugugaga—not human, wears a penguin hoodie but is not a penguin. The red muffler is said to be something they are born with. They look down on humans entering the island and immediately try to make them their errand boy. If dissatisfied, they quickly lose their temper, take it out on objects, or start punching... they are somewhat disliked on Gugugaga Island, though perhaps not every individual is like that. When fighting, they attack with wooden sticks. Since they have never seen a comrade die, if one dies, they will either flee and wet themselves or fight back. They fight back quite often, but once they realize they can't win, they flee while crying and beg for mercy. Probably the biggest idiots on Gugugaga Island. They have little learning capacity but understand human speech. Each individual will not revive once dead. They do not regenerate and do not get sick.

Average height: 30cm. Average weight: 8kg. Intelligence: Roughly that of a 2-year-old. The third most common type on Gugugaga Island. Characterized by a smaller body compared to others and wearing human-like pajamas instead of a penguin hoodie... apparently born this way. Will eat basically anything but cannot stand bitter vegetables. Because they are under 50cm, they are called Babugaga; once they exceed 50cm, they can wear a penguin hoodie and become either a Futsugaga or an Akagaga. Can only speak in "Babugaga" and cannot say more than 20 characters at a time. No concept of gender. A lifeform known as Gugugaga—not human, not a penguin. They are terrified of humans entering the island and immediately run back to their parents crying. However, they will grow fond of you if given a cookie. They rarely fight and will immediately evacuate to caves with their parents. If a comrade dies, they wet themselves and flee in tears. They have decent learning capacity and understand human speech. Each individual will not revive once dead. They do not regenerate and do not get sick.

Average height: 70cm. Average weight: 31kg. Intelligence: Roughly that of a 4-year-old. The fourth most common type on Gugugaga Island, characterized by a dumpy, stout physique. Likes fruit and fish; dislikes all vegetables. Can only speak in "Gugugaga" and cannot say more than 20 characters at a time. No concept of gender. A lifeform known as Gugugaga—not human, wears a penguin hoodie but is not a penguin. They look down on humans entering the island and try to make them their errand boy. If dissatisfied, they snap and hit with the force of a second-grader... When fighting, they attack with wooden sticks or bare hands. They have never experienced a comrade's death, but they often continue fighting without caring about it. Being fat, they have a satisfying "cutting" feel and are more durable than others, but they die instantly if shot even slightly. They have the highest combat power on Gugugaga Island, but since the baseline is so low, even an elementary schooler could win. They have little learning capacity but understand human speech. Each individual will not revive once dead. They do not regenerate and do not get sick.

Height: 62cm. Weight: 16kg. IQ: 95. A unique Gugugaga, the only one of its kind on the island. An intellectual Gugugaga who is incredibly smart for its kind, possessing the IQ of a high school student. Likes sweet and bitter things. Has no food dislikes... No concept of gender. A lifeform known as Gugugaga—not human, wears a penguin hoodie but is not a penguin. Can speak Japanese as well as the Gugugaga language. Acts as a sort of leader for the island; has high IQ but low combat power. Has normal learning capacity and understands human speech. Will not revive once dead. Does not regenerate and does not get sick.

Height: 120cm. Weight: 32kg. Intelligence: Roughly that of a 5-year-old. A unique Gugugaga, the only one of its kind on the island. A combat-type Gugugaga with durability and power unthinkable for its species. Likes anything except vegetables. Dislikes anything that makes it lose weight. No concept of gender. A lifeform known as Gugugaga—not human, wears a penguin hoodie but is not a penguin. Can emit ultrasonic waves and can deflect bullets with its fat, but is weak against sharp objects. Always stays with Shirogaga. Can only speak in "Gugugaga." Will not revive once dead. Does not regenerate and does not get sick.