Gaijatra is also known as the festival of cow. This festival is celebrated in remembrance of died people mainly in Kathmandu valley by the Newar and Tharu community. Gai Jatra has its roots in the ancient ages when people feared and worshiped Yamaraj, the god of death. However, the ironic sessions synonymous with the Gai Jatra festival entered the tradition in the medieval period of Nepal during the reign of the Malla Kings. Hence, the present form of Gaijatra is a happy blending of antiquity and the medieval era.
According to the traditions since time immemorial, every family who has lost one relative during the past year must participate in a procession through the streets of Kathmandu leading a cow. If a cow is unavailable then a young boy dressed as a cow is considered a fair substitute.