Wikipedia
Known in the Ojibwe mythology as Jiibayaabooz (also recorded as Chipiapoos or Cheeby-aub-oozoo, meaning "Spirit Rabbit" or "Ghost of Rabbit") or in the Abenaki mythology as Mateguas (Rabbit), this figure is a trickster spirit, and figures prominently in their storytelling, including the story of the world's creation. Depending on the tradition, he was either the second or third son of Wiininwaa ("Nourishment"), a human mother, and E-bangishimog ("In the West"), a spirit father.
Stories regarding Jiibayaabooz/Mateguas are filled with all things mystical and spiritual. While alive, Jiibayaabooz/Mateguas was obsessed with manidoog's and humans' interaction with each other. Through his regular communication with the manidoog through dreams, he taught the humans the importance of dreams and the methods of communication with the manidoog. As with any little brother, he was subjected to Majiikiwis' taunts, but during a dare from his eldest brother, Jiibayaabooz/Mateguas lost his life.
Even in death, his "jiibay" or ghost continued with obsession with the manidoog, and taught the humans the rites and ceremonies of vision quests and purification ceremonies. Basil Johnston, in his book The Manitous: the spiritual world of the Ojibway also adds Jiibayaabooz became the "Chief of the Underworld" and "... he bequeathed the spirit of music, chants, and poetry to the Anishinaubae peoples."
Among the Abenakis, Mateguas from the dead taught his living brother Gluskab the rites and ceremonies of vision quests and purification ceremonies to comfort his grieving brother. This became the core of the Midewiwin rituals that Gluskab then passed onto the humans.