Ukonvasara - Ukko's Hammer - or Ukonkirves - Ukko's Axe - is the symbol and magical weapon of the Finnic thunder god. In Finnish mythology the thunder god is referred to with names Ukko, Äijä or Äijö and sometimes Ilmarinen. The Estonian parallel is Uku, Vanaisa - Grandfather - or Taevataat - Sky Father.