Wakinyan--Thunder Spirit

This is a watercolor of a Wakinyan, which is a Thunder Spirit to the Lakota people.  My model was a drawing called "Dream of a Wakinyan" by Black Hawk.  He describes the picture as the Thunder Spirit riding a buffalo.  The buffalo's tail forms a rainbow.  The white spots represent hail.  If a Wakinyan visits a person in a dream, they might become a Heyoka, which is a kind of sacred clown to the Lakota.