Kwakwaka'wakw dancers use special effects to suggest supernatural powers and to excite their audiences. A cord rigging allowed a dancer to open and close this mask, creating a dramatic transformation. The exterior represents a thunderbird that, according to the beliefs of the Namgis people, completed the creation of the world. Once it is opened, the mask reveals a face—either human or snake—surrounded by two heads of the sisiutl, or lightning snake. A small man, possibly representing an ancestor or deceased chief, sits on top, and the bottom depicts a bearlike creature.