The main kami in my area is known as Omoto, and is represented by a straw serpent. Up in Izumo a similar kami goes by the name of Kojin, and it is also represented by a serpent made of rice-straw. In the Higashi izumo area these straw serpents have developed into large sculptural forms. The 2 pictured here are from Adakaya Shrine.
You won't find Kojin in the ancient chronicles as it has nothing to do with the ruling classes or the political Shinto of the shrines. It is a "folk" kami, which simply means it was/is actually worshipped by people. It is a kami that combines elements of ancestor and nature worship.
Though now in the grounds of Adakaya Shrine, these 2 altars would have been moved here during the late Meiji Period when the government closed down half the folk shrines in the country and moved them to state shrines.
The number of gohei in front of the altars, as well as the care and attention that goes into creating these straw serpents attests to the continued importance of Kojin to the local people.
The only other place I have seen such large Kojin was on the eastern side of Dogo, the largest of the Oki Islands.