What was the name of the bow given to Arjuna by Agni?

The bow given to Arjuna by Agni was Gandiva.

In the Mahabharata, Agni sought to consume the Khandava forest and asked Arjuna and Krishna to help him withstand the gods and other beings who might intervene. Arjuna agreed, but requested weapons suited to his exceptional skill as an archer. Agni obtained the divine bow Gandiva from Varuna, along with two inexhaustible quivers, and presented them to Arjuna.

Gandiva was not an ordinary weapon. Epic tradition describes it as a celestial bow made by Brahma and held successively by major deities before reaching Varuna. Its possession helped establish Arjuna as one of the central warriors of the Pandava side. During the Kurukshetra War, he used it against formidable opponents including Bhishma, Drona and Karna.

A common mix-up is Sharanga, the bow associated primarily with Krishna, and Pinaka, Shiva’s bow. Gandiva belongs specifically to Arjuna. At the end of the epic, after Krishna’s departure and the destruction of Dvaraka, Arjuna’s divine weapons lose their former effectiveness; he eventually returns Gandiva to Varuna.