According to the Kalika Purana, Bhairava is identified as the human manifestation of Mahakala, while Vetala is considered the human form of Bhringi. Mahakala and Bhringi, sons of Hara, originated from two drops of his spilled semen, possessing a deep black hue that inspired their names. Appointed as guardians by Shiva and Parvati, the duo stood watch as the divine couple reveled in their privacy.
During one of Parvati's disheveled exits from their abode,
Mahakala and Bhringi, catching sight of her, incurred her wrath. Cursed for
witnessing her in a state meant solely for her husband, they were condemned to
be reborn as humans with simian visages. Refuting the unjust curse, they
retaliated, blaming Parvati for her inappropriate exit and insisting on their
innocence. Their counter-curse dictated that she would be reborn as a human
with Hara as her husband, with Mahakala and Bhringi as her sons.
In adherence to this fate, Parvati reincarnated as Princess
Taravati, born to King Kakutstha and Queen Manonmathini. Her marriage to Prince
Chandrashekhara, an incarnation of Shiva, followed. A twist unfolded when Sage
Kapota, captivated by Taravati's beauty, sought a union with her during her
bath. To protect her virtue, Taravati sent her sister Chitrangada in her stead.
The ruse persisted until the sage discovered the deception, prompting him to
curse Taravati.
According to Kapota's curse, a repulsive, destitute man
bearing a skull would forcibly father two monkey-faced sons with Taravati.
Furious at the curse, Taravati vowed that only her husband, Chandrashekhara,
would have the privilege of intimate relations with her. In response,
Chandrashekhara built a secluded tower for her residence.
Seizing an opportunity to fulfill the curses, Shiva and Parvati, in disguise, encountered Taravati. Shiva assumed the guise described in Kapota's curse, resulting in the birth of two monkey-faced sons through their union. Sage Narada later informed the king of the truth about the princes' divine origin, and they were named Bhairava and Vetala.
Despite the king's affection for his other sons, Bhairava and Vetala invoked fear. Opting for an ascetic life, they roamed the forests until Sage Kapota revealed their true parentage. Sent to Kamarupa to meet their divine parents, they worshipped Parvati and Shiva, receiving blessings of eternal servitude, immortality, and divinity. Shiva bestowed upon them Ganeshatatva, sealing their connection to the divine couple.