Beast With Five Fingers, The by W. F. Harvey (1885 - 1937)

A well off English bachelor receives a legacy from his uncle. This includes the uncle's very large library and a box containing something that used to belong to his uncle. The box has air holes in it. It is not a rat or other small mammal for his collection, but it is something still alive; something very malevolent and something very evil. - Summary by Phil chenevert