According to some Puranas, Lord Shiva took the form of Sharabha to pacify and control the Narasimha Avatar of Lord Vishnu. If Lord Vishnu as Narasimha was half-man half-lion; Lord Shiva as Sharaba was part human, part animal and part bird with numerous claws and legs – some writers equate the form to a dragon. Sharabha manifestation of Lord Shiva is not very popular and there is popular notion that this incarnation of Shiva was created to position Shiva as greater than Vishnu by some Shaivites.
Lord Narasimha's terrifying rage could not be dissipated even after He had slain the Demon King Hiranyakashipu. A more ferocious form of Sharabha was able to pacify Narasimha Vishnu. Soon Vishnu appeared in the pleasant form before his devotees.
Shiva Purana describes the Sharabha for like this:
He had a thousand hands and wore matted locks. His head was adorned by the crested moon. He appeared like a bird with wings and beak. His body was fierce and fully developed.
His fangs were very sharp. Adamantine claws were His weapons. His neck was black in colour. He had huge arms and four legs. He was blazing like fire.His voice was resonant and terrible like the rumbling sound of the clouds that gather at the end of the yuga. His three eyes were wide and blazing as the fire of the evil spirit of great fury.His fangs and lips were clearly visible. He was producing a hissing sound of humkara. Shiva of such a form appeared in sight.
This fierce form of Shiva is also known as Sarabheswara. The image of two Sharabhas guarding the entrance of Shiva temples is common in many South Indian temples.