The traition of Gog and Magog (Hebrew גוג ומגוג) begins in the Hebrew Bible with the reference to Magog, son of Japheth, in the Book of Genesis and continues in cryptic prophecies in the Book of Ezekiel (see War of Ezekiel 38-39), which are echoed in the Book of Revelation and in the Qur'an. The tradition is very ambiguous with even the very nature of the entities differing between sources. They are variously presented as men, supernatural beings (giants or demons), national groups, or lands. Gog and Magog occur widely in mythology and folklore.