An Eritate-goromo (literally, standing-collar robe) is one of Japanese yokai (ghosts, spirits and monsters) that was portrayed in Sekien TORIYAMA's yokai art collection book: "Gazu Hyakki Tsurezure Bukuro" (The Illustrated Bag of One Hundred Random Demons; the term 'hyakki' in its title is a pun on the usual hyakki, replacing the character for demon which is written as "鬼" in Japanese with a character for vessel written as "器," and sure enough, most of the yokais shown in this book are tsukumogami [a type of Japanese spirits that originate in items or artifacts that have reached their 100th birthday and become alive]).
Sojobo of Mt. Kurama (also called Kurama Tengu), one of the eight greatest Japanese tengu (long-nosed goblins), used to wear a clerical robe with a standing collar, which reportedly transmuted into a yokai and was thus named the Eritate-goromo. In TORIYAMA's book, the Buddhist priest's robe worn by Sojobo has eyes and a beard on it, and its sharp collar forms the Eritate-goromo's nose.
The Sojobo of Mt. Kurama used to be a human high priest. According to a legend, Sojobo mistakenly believed that he suddenly realized Buddhahood in the middle of ascetic practices, thereby failing to become Buddha after death. According to one view, he was reincarnated as tengu, which is a synonym for arrogance. Although he became a tengu, he still wore the priest's robe as if he persisted in the dignity as a priest. The robe may be a proof of his arrogance. It is supposedly either Sojo's fatal arrogance or the possession by an evil spirit that caused the robe to turn into a yokai: the Eritate-goromo.