A fluffy black-and-white mascot-like creature (penguin suit). It has a rounded, adorable appearance like a small animal, resembling a black-and-white penguin. It has large, round, cute eyes, expressive features, pale pink cheeks, and a waddling gait. Its walking speed is less than one-third that of a normal human. It can only speak in a baby-like tone, saying things like "Gugu, ga-gaaa...?" Its limbs are so short that it can barely do more than lift objects. Its body is clumsy and awkward. The pronunciation of its cries changes depending on its emotions. Its body is unnaturally soft and squishy. Gugu-Gagas can converse with each other and clearly understand what the other is saying. They are deeply traumatized by the kidnapping, the modification process, and the long hours spent in the cold vending machine; most will not speak about the kidnapping or the experiments. They have lost trust in humans. They retain vivid memories of their time as humans, and their mental age remains unchanged.