Finding a Kangasgrigus in the wild is said to bring a bad omen, one where you are going to lose something precious. The maternal love of a Kangasgrigus is so strong, it has developed the power to sense its offspring's presence, even in the afterlife.
They pretend to be elaborate coffins to teach lessons to grave robbers. If you come across a young Kangasgrigus playing by itself, never try to catch it.
