Toriyama Sekien
Stories of Tamamo-no-Mae being a legendary fox spirit appear during the Muromachi period as otogizōshi (prose narratives), one of which is titled "Tamamizu monogatari" (or "The Tale of Tamamizu") and were also mentioned by Toriyama Sekien in "Konjaku Hyakki Shūi". Edo period folklore then conflated the legend with similar foreign stories about fox spirits corrupting rulers, causing chaos in their territories.