Gada, or mace, is a very popular weapon in Hindu scriptures. Gada was the favorite weapon of Bhima and Duryodhana in the Mahabharata. The story of the origin of Gada is found in the Agni Purana, Chapter 114.
Gada was a demon. He was the son of Sage Kashyapa and Diti. The demon was killed by Lord Vishnu to protect Dharma.
Vishwakarma, the divine architect, made a weapon from the bones of the demon. The weapon was mace. Since the weapon was made from demon Gada’s bone, it came to be known as Gada.