Wikipedia
The Agropelter (Anthrocephalus craniofractens) is a mythical fearsome critter said to inhabit hollow trees of the conifer woods from Maine to Oregon. From this vantage point, the creature would await an unwary person and hurl wooden splinters and branches at the intruder. Some have described the creature as being so quick that it has never been seen. One reference describes the creature as having a "slender, wirely body, the villainous face of an ape, and arms like muscular whiplashes, with which it can snap off dead branches and hurl them through the air like shells from a six inch gun." The Agropelter subsists on woodpeckers, hoot owls, high-holes, and dozy (rotten) wood. Its pups are born on February 29 and always arrive in odd numbers. They are blamed for the disappearance of people in northern forests. Loggers who died when branches fell on their head, agropelter was blamed for throwing the heavy branch on their head.