According to Sumerian folklore, Kishnar is the master of earth and fire. He appears every 1,000 years to do battle with Anshar to determine who would rule the Earth.
Kishnar and Anshar knew that since they were immortal, neither of them could die and as a result, their battles always ended in a tie and ironically preserve the natural balance of the world.
Eventually, Anshar had the idea that they possess two humans to fight to the death, determining who would win.
When the Ghostbusters were stranded on their island, Kishnar possessed Ray Stantz and Anshar possessed Peter Venkman.
Whenever Ray and Peter got angry or started to fight (escalating their negative energy), they would transmutate into corporeal manifestations of Anshar and Kishnar. The two demons were eventually defeated when the other Ghostbusters kept them from destroying one another until sunrise, causing the two demons to go dormant for another 1,000 years.
- Kishnar's name is an anagram or a corruption of the name of the Hindu god Krishna.