Story of Uttar
Prince Uttar was the son of Virat, the Matsya King. In the last year of their exile, Pandavs chose to stay in disguise in the Matsya kingdom. It was after Keechak's death that Susharm attacked Matsya. As King Virat's army marched to confront Susharm, the young Uttar stayed back at the palace. In the meantime, Duryodhan attacked Matysa from the other side and took control of the cattle. The overconfident Prince Uttar decided to face the Kauravs with Brihannala (Arjun in disguise) as his charioteer. But, when he saw the powerful Hastinapur army, he got frightened and started to run away. It was then that Arjun revealed his true self to Uttar and they exchanged places; i.e. Uttar became the charioteer and Arjun fought and defeated the Hastinapur army