From Ojibwa Folklore
Once, a long time ago, before the white man came to Canada, an Indian struck out through the bush to hunt. It came on a storm and he took a line for camp, which was by a little lake away up north. It came on worse, and the Indian crawled under a projecting pine tree. He saw the lightning strike several trees, and looking very closely at one tree that was struck he saw a little man (about two feet high) standing by one side of the tree, and looking again at the tree he saw another little man standing at the other side of the struck tree. Both these men were fine little fellows, all black and shining, and are called Nim-Mah-Kie (Thunder). They climbed up in the air, like they were climbing ladders, and disappeared. After they went up more lightning came down. These little men set the lightning at the trees and make the thunder. Thunder and lightning keep the monsters down on the land and in the lakes.
These monsters, which are about twelve feet long and about one and one-half to two feet thick, and which have long jaws full of teeth, and look like half fish and half snake, live in hills near lakes. They have underground passages from the hills to the water, and can sometimes be seen early in the morning. In small lakes and bays of larger lakes they move around with great swiftness, forcing the weeds and floating sticks, etc., up high on the shore, similar to swirling your hand around in a wash basin. Sometimes they do this with so much force that they leave the small lakes partially dry. One of these monsters lives in the hill just north of where the old Indian portage from Lake Simcoe enters West Bay, Balsam Lake. Another lives in the hill at Atherley, Rama Reserve, Lake Couchiehing, and another lives up north in a lake, the name of which is now forgotten. Thunder and lightning kill these monsters.
Source:
Ojibwa Myths and Tales, G.E. Laidlaw, 1915
Kotharian Lightning 