in Baltic religion, the heavenly smith, usually associated with a huge iron hammer. A smith in the tradition of the Greek Hephaistos and the Vedic Tvaṣṭṛ, Kalvis also seems to have been a dragon killer, a function in which he was superseded by the Christian St. George. Every morning Kalvis hammers a new sun for Aušrinė (Latvian Auseklis), the dawn, and a silver belt and golden stirrups for Dievo sūneliai (Latvian Dieva dēli), the morning and evening stars.

Kalvis' extraordinarily large iron hammer, by whose aid the sun was said to have been freed from imprisonment, was honoured by the Lithuanians as late as the turn of the 15th century.