What object from Ojibwe mythology is used to protect sleepers from bad dreams?

The object from Ojibwe mythology used to protect sleepers from bad dreams is a dreamcatcher.

A traditional dreamcatcher is a small hoop, usually made from willow, with a woven web or net across its center. It is associated especially with Anishinaabe peoples, including the Ojibwe, and was traditionally hung near a cradle or sleeping place. Popular explanations say the web catches harmful dreams while beneficial dreams pass through toward the sleeper.

Ojibwe accounts also connect the object with Asibikaashi, often called Spider Woman, a protective being associated with caring for children. As Ojibwe communities spread across a wide area, mothers and grandmothers were said to make web-like charms so children could remain protected. Ethnographer Frances Densmore recorded Ojibwe protective spiderweb charms in the early 20th century.

The familiar dream-focused explanation is not the whole historical picture: early descriptions emphasize protection from harm generally, rather than only nightmares. Dreamcatchers later spread through the Pan-Indian Movement of the 1960s and 1970s and became widely commercialized in the 1980s. They are therefore not a generic symbol representing every Indigenous nation.