Kaichigo' refers to a type of Japanese spirit appearing in "Hyakki Tsurezurebukuro Hyakki Tsurezure Bukuro' (One hundred bags in idleness), collections of ghosts, spirits, spooks and monsters, described by Sekien TORIYAMA.
貝児（かいちご）は、鳥山石燕の妖怪画集『百器徒然袋』にある日本の妖怪。