Shivas most terrifying and angry manifestation is as Bhairava, who usually is depicted naked and horrible with fangs and weapons and carrying a skull. His very name is synonomous with fear. Bhairava has the power to conjure up our worst fears and force us to confront them. He is also a most powerful protector against harm, and is often painted in villages to ward off evil spirits.
Sometimes Bhairava is depicted with the face or form of a dog, but usually a dog is his vehicle. Yes, that's right, this aspect of Shiva gets around the universe on a dogs back. There are Bhairava temples all over India, where offerings are made to both statues of dogs and living dogs. One of the largest temples to Kal Bhairava in Varanasi shows images of Shiva astride a big white dog. Inside his temple there live dogs who freely wander inside and out. Pilgrims worship the dogs and decorate them with garlands of doughnuts and other things delicious to dogs to eat, which the dogs of course immediately shake off and eat.
Achieving Moksha through Bhairava Shiva
The lesson that Bhairava Shiva wishes to teach you through human pup play is that all phenomena, material and mental, is an illusion that serves a purpose to help set you free. By pretending to be a dog, you are creating an illusion. Your pup self is a falsehood. Yet, you grow to care for your pup self, developing feelings of desire and attachment for it. Bhairava Shiva helps you destroy and create these selves, and it is Shiva's will that holds you safe in the midst of all this illusion. It is his lesson to you that it is all made up - it all comes from in your head - your human self, your pup self. And you can learn that what you experience of the world is translated through a lens of selfness, whether it be human or pup. And you can put down that lens and no longer engage with the material world, with phenomena, as so very important and impactful. You no longer have to feel and react to everything, and you can set yourself free of petty things and issues and experience that holds you back. You don't have to take everything so personally, as the world will matter less to you, as you connect with the divine from within you and through your Master. This is Moksha, where you grow in wisdom from experience and see the universe more clearly, you become more enlightened and closer to Shiva and the cosmic all.
Shaiva Siddharta is similar to Tantric Shiva, and it is the core of Shvan Yoga. Your path is for your release from lust and hatred and enlightening yourself to the divine. Ironically, this is done by making yourself into a beast, a dog, so you can then can be released from that.
The essential element of Shvan Yoga is using human pup play to engage in bestial behaviour. You must behave like a dog. This is the outward manifestation. From within you must delude yourself to embrace the condition of the beast, you must imagine and create your pup self and believe in it. So before a pup play session you embrace Bhairava Shiva as your protector, you place yourself in his divine power and hands as you let yourself go and become a dog.
Once you have become a dog, inside and out, you will find that you have an opportunity to reveal your own bestial animal nature, with the passions that secretly manipulate and influence you from within, such as lust and hatred, which you can then be released from. This happens in its own time, developing through the experiences you get through in pup play. You will come out of a pup play session, and be able to seek Bhairava Shiva's blessing and be safe to contemplate what the experience has taught you. If you follow the path of Shvan Yoga, and do your Niyamas, avoid the Yamas, and live the Four Fundamentals - your spirit will slowly but surely be set free from the anguish and torment of petty concerns, and you can allow the negativity and hurt to be taken away. You will achieve peace from Shvan Yoga as Bhairava Shiva inspires you to destroy your selfness, and create it again, and to regenerate and heal in that process.