The ancient text Shakti Sangam Tantra in its Kali Khand chapter has mentioned the origin of Lord Batuk Bhairav. According to the text, once a demon named Aapat had gained powers through Sadhanas and he used it to harass everyone including the gods. The gods then got together and started to think of ways to find a solution to this problem. As they started concentrating, their powers appeared as a flash of light and took the form of a five year old child, Batuk. The child, then, killed the demon and saved the gods which is why he is known as Aapat Uddharak Batuk Bhairav.
In tantra and other Hindu puja, this is the most worshiped form of Lord Bhairav among the various forms of Bhairav. All other forms of Bhairav are terrifying apart from this as this is in the form of a child. He is also known as the child form of Lord Shiva. The image of Batuk Bhairav is displayed with a dog accompanying him, which is symbolized as dharma