Ghantakarna was created by Lord Shiva to help Goddess Bhadrakali overcome smallpox. He had the power to lick smallpox out a person’s body. The demon wore bells in his ears hence the name Ghantakarna.
Ghantakarna wrongly believed that Lord Vishnu was his enemy. Here therefore put bells (ghanta) in his ears (karnas) to not to hear the name Vishnu. However, Shiva revealed to Ghantakarna that all manifestations are the essence of the Suprme.
He then became a devotee of Vishnu and chanted the name of the Lord to attain salvation.
Ghantakarna is believed to have met Sri Krishna at Badaryasrama and here he witnessed the Vishwaroopa. After this incident, Ghantakarna attained moksha and entered Vaikunta.
Some Vaishnava temples have the image of Ghantakarna. In the sculptures, he has eighteen hands. He is offered prayers for cure of diseases.