death cookie
n.— «The waiver releases McGowan from all liability should I fall victim to any kind of accident, including a sudden avalanche, “death cookie” (the ice-packed snow that build up on top of the trees here) or tree-well (a hole that forms under a light cover of snow just around the tree trunks).» —“Skiing thigh-high in powder You don’t have to be an expert; you need guts and few brains” by Anita Latner Toronto Star (Toronto, Canada) Jan. 7, 1989. (source: Double-Tongued Dictionary)