Ravana

Rāvaṇa is the rākṣasa king of Laṅkā, son of the sage Viśravā and Kaikasī and half-brother of Kubera; from his ten heads he is called Daśakandhara and Daśānana. By Brahmā's boon he was unslayable by gods, dānavas and yakṣas, and he harried the three worlds, but was killed by a man, whom he had thought too slight to name. The carrying off of Sītā was his decisive crime. SB 2.7.23 says that opposing Rāma he 'came to grief'; and SB 2.7.25 describes his strength, that by the touch of his chest the tusks of Indra's elephant were broken — by which his defeat is shown the greater.

Śrīmad Bhāgavata Mahāpurāṇa 2.7.23 — Sanskrit Wikisource (pinned oldid=200170)