Bhikshatana Shiva is a form of Lord Shiva in which he became a naked mendicant and wandered all over the world asking for alms. There are different stories behind why he assumed this form.

1. The Story of Bhikshatana (Shiva Purana, 4.12):

Once upon a time, there was a forest named Daruvana. There were many sages who were devotees of Lord Shiva. One day some of them went into the jungle to bring sacrificial twigs. To test their devotion, Lord Shiva assumed a very hideous form. He was stark naked and had smears of ashes all over his body. He came to the houses of his devotees, held his penis, and started showing all sorts of vicious tricks. The wives of the sages got scared at this sight, but the other women, excited and surprised, approached him. Some embraced him, and some held his hand.

Meanwhile, sages returned and were infuriated at this sight. Therefore, they cursed the Lord that his penis would fall on the ground. The curse was immediately fulfilled and the Lord’s penis fell, but that penis started moving randomly and burnt down everything that came in its path. It went to all three worlds (Earth, heaven, and netherworld), and the people were distressed. After this also, they did not recognize Lord Shiva and went to Lord Brahma for help. He told them that the person they cursed was Lord Shiva, and the problem would not be solved until the penis became stationary. He also told them that only the goddess Parvati could do this.

Then, all gods propitiated the goddess Parvati, and she held Lord Shiva’s penis in her genitalia and the penis became static. When the phallus was stabilized, there was welfare throughout the world. Therefore, the people who worship Lord Shiva in this form become happy in all respects.

The same story with slight variations is mentioned in the Vamana Purana, Skanda Purana, and Matsya Purana, but the story in the Linga Purana is a bit different. According to the Linga Purana (1.29), the sages said harsh words to Lord Shiva but could not curse him because their power of austerity was ineffective against him. Lord Shiva disappeared from there then.

In the morning, all the sages with perplexed minds went to Lord Brahma and informed him about the incident. Lord Brahma told them that he was Lord Shiva to whom they spoke harsh words and told them to worship Shiva lingam and take penance. So, the sages took penance for a year, and then Lord Shiva forgave them and appeared in Daruvana again. Then, Lord Shiva told them that he took this hideous form to teach people not to ill-treat the ascetics even if they roam naked around.

2. Lord Shiva Cuts the Head of Lord Brahma:

Many Puranas mention that Lord Shiva cut off the fifth head of Lord Brahma, but there are different reasons given in different Puranas. Per the Kurma Purana, once in a council of sages, Lord Brahma declared that he was the Supreme God. At that time, Lord Shiva appeared there in the form of an infinite pillar of light and challenged Lord Brahma’s claim. After a thorough discussion, the sages agreed that Lord Shiva was the Supreme God, but Lord Brahma arrogantly declined to accept it. Therefore, the infuriated Lord Shiva cut off one of his heads.

Per another version of the story, Lord Shiva cut off the fifth head of Lord Brahma because it was condemning the Vedas. Per the Skanda Purana, he did so because Lord Brahma married his own daughter, Saraswati.

Whatever may be the reason, afterward, Lord Shiva was remorse cutting the head of Lord Brahma and wanted to atone for the sin. Because of the sin of Brahmahatya, the head of the Brahma stuck to his left palm. Therefore to expiate the sin, Lord Shiva became a Kapali and wandered the world as a naked beggar using the skull as a begging bowl.

Lord Vishnu Helps Lord Shiva:

Per the Kurma Purana, after the encounter with sages in Daruvana, Bhikshatana Shiva continued to wander until he reached Vaikuntha, the abode of Lord Vishnu. The guard of Vaikuntha did not allow him to visit Lord Vishnu. Therefore, Lord Shiva killed him and hoisted his corpse on his trident. He entered Vaikuntha and begged for food. Lord Vishnu offered him his blood as food and advised him to go to Varanasi, where his sin would be expiated.

Upon reaching Varanasi, the skull of Lord Brahma fell off his palm at a place called Kapala Mochana. The corpse of the guard also disappeared from his trident. After bathing in the sacred pond of Varanasi, he cast off his appearance of Bhiskhatana Shiva. Then, he assumed his original form and returned to his abode.

Image Source: Wikipedia