Nobody can say for sure who invented the dream catcher. However we do know it originated from North America where the original natives who spoke Ojibwe first began crafting them. They have always been decorated with string and feathers and have remained in the same shape and style although there are many modern takes on which change this but it has more or less stayed the same.
The Ojibwe speaking natives believed that the dream catcher came from a spider woman in a vision from a tribe leader and was told to begin making them to protect themselves from terrible dreams and bad visions. The tradition has stuck and now many of us to this day use dream catchers to protect ourselves from those awful nightmares.