While wandering the woods, they accidentally break a sacred circle, releasing a terrible monster: the Wendigo.
It was recorded by Mackey 'Avatar' McCandlish and Brian 'Wendigo' Hess and released at 11pm ET on Monday 8 December 1997.
Elbow Witch is Monster in My Pocket #63, one of only three monsters derived from Native American mythology, the others being Wendigo and (to an extent) Bigfoot.
That rugaru story bears some resemblance to a Native American version of the wendigo legend related in a short story by Algernon Blackwood.
The Curse of the Wendigo is a 2010 young adult horror novel by Rick Yancey.