Keukegen ("fluffy hair appearance") is a creature in Japanese folklore, resembling a small dog covered entirely in long, dirty hair. Keukegen are particularly filthy monsters commonly found in populated areas. The keukegen is a minor spirit of bad luck, disease, and pestilence which lives in cool, damp, dark places and causes people in the house to get sick.
They are are particularly fond of living under floorboards and around run-down homes, where stuffiness, moisture, and lack of human activity create the perfect breeding place for sickness. Generally they try to avoid human contact, being shy by nature, and are rarely seen. They are easy to avoid, however, as keep away from clean, kempt houses.
Its name is a pun - when written with different kanji (希有怪訝), keukegen means "an unusual thing which is rarely seen." It was first illustrated in Toriyama Sekien's Konjaku Hyakki Shūi.
