 It is likely that the figure of Ukko is mostly Indo-European, possibly Baltic, in origin.Ukko is held by researchers of religion to be parallel to Indo-European patriarchal sky deities, for example to Zeus and Jupiter of the Classical Greco-Roman pantheon, the Indian Hindu god Indra, Slavic God Perun and the Norse god Thor.Tuuri, a Germanic loan and cognate of Thor, was possibly an alternate name for Ukko.