Gosha is the maternal grandfather of the protagonist, Legoshi, and a Komodo dragon. He is a tall, elderly reptile with an athletic build, his body entirely covered in green scales. His eyes are narrow with small irises, a trait he passed on to his grandson, and he possesses a long, deeply forked tongue. Despite his formidable and intimidating appearance, his typical clothing is simple and practical, often consisting of a striped shirt and trousers. Known affectionately by his neighbors as the "scaly old gentleman," he maintains friendly relationships with the children and residents in his area.

In his youth, Gosha was a figure of significant renown and fear known as the "dreadful Komodo dragon," a mercenary who appeared wherever species conflicts arose. Seeking a new path, he teamed up with Yahya, acting as his trusted partner to fight crime and maintain public safety, with the shared dream of becoming a Beastar. He was known for his strong sense of justice and disregard for material honors like medals. This all changed when he and Yahya rescued a female gray wolf named Toki, with whom he fell deeply in love. Choosing family over his ambition, he abandoned his dream of becoming a Beastar to settle down with her, leading to a permanent rift with his former partner.

Gosha's defining characteristic in the present is a calm and gentle nature, preferring to avoid conflict whenever possible. He is a dedicated pacifist who taught these values to Legoshi, but he is also a fierce protector who does not hesitate to use overwhelming force when his family is threatened. He lives with a deep, ingrained caution due to his venomous nature, going to extreme lengths to prevent harming others. This includes carrying his own utensils to restaurants, always sitting in inconspicuous seats, and in the past, obsessively disinfecting his wife's skin after kissing her. This deep-seated fear of his own biology is a source of trauma, especially after the death of his wife. His motivation is almost entirely centered on family; his actions are driven by a profound sense of responsibility and love for his descendants.

Gosha's role in the story is that of a supportive, if initially distant, guardian and a link to the past. After the death of his daughter Leano, he became Legoshi's primary caretaker. However, after a painful argument where a grieving Legoshi blamed him for Leano's suicide, Gosha sent his grandson to Cherryton Academy and they became estranged for five years. Despite the separation, he secretly and consistently cares for Legoshi, working as a construction worker and volunteering on weekends at a daycare for hybrid children, reflecting his compassion for those facing similar struggles of mixed-species identity. His reunion with Legoshi is a pivotal moment, allowing him to offer guidance and support. A key relationship is his complicated friendship with Yahya, who resents him for abandoning their shared dream, yet Gosha still considers him a dear friend. His entire life is shadowed by his tragic romance with Toki, who eventually died after deliberately kissing him without the protective disinfectant, considering it a victory to have loved him fully.

Gosha possesses several notable abilities. As a Komodo dragon, he produces a powerful venom from glands in his mouth, which can cause shock and unconsciousness on contact. He is extremely careful with this venom, but when his anxiety is heightened, particularly concerning Legoshi, the venom becomes more concentrated and takes on corrosive properties potent enough to melt through concrete and steel. He is also an exceptionally skilled close-quarters combatant, using his powerful tail, sharp claws, and agile, ferocious movements honed from his years as a vigilante. His venomous nature also grants his direct relatives, including Legoshi, a natural immunity to its effects. Furthermore, he can detect enemies by flicking his tongue, a tactic he used as Yahya's partner to cover his one blind spot in a fight.