In the Mālābāra district, a section of the brāhmaṇas are known as Nambudari brāhmaṇas, and the Bhaṭṭathāris are their priests. Bhaṭṭathāris know many tantric black arts, such as the art of killing a person, of bringing him under submission, and of destroying or devastating him. They are very expert in these black arts, and one such Bhaṭṭathāri bewildered the personal servant of Śrī Caitanya Mahāprabhu while the servant accompanied the Lord in His travels through South India. Somehow or other Śrī Caitanya Mahāprabhu delivered this Kṛṣṇadāsa from the clutches of the Bhaṭṭathāri.
Ref >> Srila Prabhupada Vani.