Koja was the runt of his mother's litter. He was nearly eaten by his mother, but convinced her to keep him alive by emphasizing his ugliness compared to her beauty. After two years, the other animals named him Koja, meaning "handsome", as a joke.
Using his clever wits, Koja escaped many would-be fatal situations. When he became stuck in a farmer's trap, Koja was picked up by the bloodthirsty bear Ivan Gostov, but escaped by convincing the bear's flees to attack him. A year later, Koja gave Ivan Gostov kvas and chicken, and the two animals became friends.
When Ivan Gostov disappeared one winter, Koja asked the nightingale Lula to investigate the nearby town of Polvost. Lula told the animals of the arrival of the infamous hunter Lev Jurek and his sister Sofiya. At night, Koja snuck into town and found Jurek and Sofiya in a tavern, sitting on a rug made from Ivan Gostov's hide. Koja watched Jurek for several days, attempting to discern the reason for his success, and decided the hunter must be using magic.
Koja followed Sofiya on her regular pilgrimage to the old widows' home. When she stopped to cry in a clearing, Koja spoke to her, telling wild stories and making her laugh. On Sofiya's next trip, she told him that her brother would not let her take a husband, and gave Koja cheese. On their third meeting, Sofiya told Koja that her brother wore a magic charm; Koja asked her to steal it from him to free them all from Jurek's trap, but he had to devise a way to ensure Jurek would not wake up in the night. He gathered dropwort as a sedative and encouraged the other animals not to flee the woods near Polvost, since the hunter would soon be gone.
Koja gave Sofiya the dropwort leaves and instructed her to steal Jurek's magic charm as he slept. The next day, Sofiya showed Koja the charm and they celebrated with wine and cheese. Happy, he fell asleep in Sofiya's lap. Sofiya bound Koja's paws and began to cut off his coat with her knife. She revealed that she, not her brother, was the silent hunter, who lured her animal victims into the trap of conversation with her. With no more clever escape plans, a dying Koja cried out. Lula answered his call and pecked out Sofiya's eyes.
Koja survived, albeit with a damaged coat, and became more careful when dealing with humans. He and Lula made a quiet life together.
Personality and traits
Koja was known for his cleverness and his ability to escape traps. He understood the motivations of people and animals and used this knowledge to manipulate them into either helping him or leaving him alone. Koja often used his ugliness to steer others into the directions he wanted them to go. He liked to tell stories of his successful escapes. Ana Kuya's version of the folktale portrays Koja as "smart enough to get out of one trap, but too foolish to realize he won’t escape a second."
Koja was a small and scrawny fox with a patchy coat. He had large ears and big yellow eyes.
- Siege and Storm, chapter 2