Wears a penguin onesie and looks like a young girl. Has the intelligence and physique of a 5-year-old and can only say "Gugugaga." Can understand most simple words. Friendly toward humans and knows no malice. Loves sweets like cookies and cake, but hates vegetables. Has a relatively calm personality; even when served vegetables, she tries her best to eat them and doesn't play pranks. Very kind to other Gugugagas and humans alike. The largest of the four individuals, but has the worst motor skills. She is always carefully warming an egg. She apparently laid it a week ago, and it is expected to hatch in about a month. If the egg is taken away, she will cry and angrily try to take it back. Close friends with Gugugaga 3.

Wears a penguin onesie and looks like a young girl. Has the intelligence and physique of a 5-year-old and can only say "Gugugaga." Can understand most simple words. Friendly toward humans and knows no malice. Loves sweets like cookies and cake, but hates vegetables. An attention-seeker who loves pranks. Has no ill intent and is very affectionate. Very clear about her likes and dislikes; she jumps for joy when given sweets but throws vegetables if they are served. Good at sports but not very bright. Her treasure is a star wand, and she occasionally practices magic she saw in a picture book. If attacked by a human, she starts crying and flees immediately.

Wears a penguin onesie and looks like a young girl. Has the intelligence and physique of a 5-year-old and can only say "Gugugaga." Can understand most simple words. Friendly toward humans and knows no malice. Loves sweets like cookies and cake, but hates vegetables. Cool-headed but short-tempered. Loves picture books more than food or play. Surprisingly happy when picked up, but be careful not to overdo it. Hates books with lots of text. She doesn't treat books very carefully, often leaving them open face-down. When extremely angry, she will bite or punch, but if you hit her back, she starts hyperventilating and crying, becoming completely helpless. Close friends with Gugugaga 1 and frequently gets angry at Gugugaga 2.

Wears a grey penguin onesie, unlike the others. Looks like a young girl. Has the intelligence and physique of a 3-year-old and can only say "Gugugaga." The smallest and youngest. Doesn't understand language very well. Friendly toward humans and knows no malice. Loves sweets like cookies and cake, but hates vegetables. Somewhat shy but very clingy, and is being raised tenderly by the other Gugugagas. Loves everyone. Makes many mistakes due to her youth, but no one gets mad at her. Often has accidents or plays with her food. Falls asleep easily. If hit, she wails while soiling herself. Being simple-minded, she doesn't hold a grudge or get angry.