The Great Spirits are characters who make the magical changes; they have the spirit of Sitka turn Kenai into a bear in Brother Bear as punishment for killing an innocent bear that didn't kill Sitka and Nita into a bear in Brother Bear 2 because she wants to marry Kenai instead of Atka. The Great Spirits were believed to be the "gods" during early American formation and also in Canada. With high beliefs of the animal transformation after death, the spirits appear for the first time to Kenai in the form of several animals appearing in the bright colored sky above him. Sitka, Kenai's brother whom passed was transformed into an eagle for the guidance he must give in honor of his totem. Kenai is to create more love and care for others, of which he recieves the bear totem from the Great Spirits.
All the animals in the Great Spirits represent the totem of a person when he/she was alive. They show that animals too are alive and can have feelings just as a man. In Kenai's case a man can learn more from the life of animal.