From Hindupedia, the Hindu Encyclopedia
By Swami Harshananda
Kalmāsapāda literally means ‘one with black feet’.
The king Saudāsa of the Ikṣvāku dynasty was once tricked by a demon while serving his guru Vasiṣṭha with human flesh. He was consequently cursed by the angered sage to become a cannibal-demon. Saudāsa was now called Kalmāṣapāda since his feet were black. He ate up all the sons of Vasistha. However, after twelve years the curse was over. Sage Vasiṣṭha was kind enough to bless him with a good son to succeed him.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore