Kosamebo is a specter handed down in Japan and looks like a figure of a Buddhist priest.
According to "Konjaku Hyakki Shui (Ancient and Modern Gleanings of the Hundred)" written by Sekien TORIYAMA (see the right picture), Kosamebo appears on a drizzling rainy night in Mt. Omine, the sacred mountain of Shugendo (Japanese mountain asceticism-shamanism incorporating Shinto and Buddhist concepts) and Mt. Yamato Katsuragi, and begs practitioners of Shugendo for food.
According to "Tohoku Kaidan no Tabi (Trip to the scary stories in Tohoku region)" by Norio YAMADA, a Kosamebo begged a traveler for some millets on a rainy day in 1671 on a kaido (main road) deep in the mountains in Tsugaru region. The recent books on specters sometimes use the illustration based on Sekien's picture and the caption is added that Kosamebo is a specter that begs for travelers for millets. However, Kosamebo in "Tohoku Kaidan no Tabi" is in Aomori Prefecture, and it is said that it has nothing to do with Kosamebo in Mt. Omine and Katsuragi (Kinki region).