Panchajanya

The Panchajanya is Krishna's conch, obtained after slaying the asura Panchajana who had taken the form of a conch — whence its name. It is one of the four emblems of the Lord's four-armed form and the sign of His proclamation and summons. Its blast at the opening of the Mahabharata war tore the hearts of the Kaurava army. At SB 1.11.1-2 Krishna sounds it on reaching Anarta, and reddened by the crimson of His lips it shines like a swan calling amid a cluster of lotuses; its note is called 'that which strikes fear into the world's own fear'.

Śrīmad Bhāgavata Mahāpurāṇa 1.11.1 — Sanskrit Wikisource (pinned oldid=110182)