Otoroshi

[1][2] According to the Edo Period writing Kiyū Shōran (嬉遊笑覧), it can be seen that one of the yōkai that it notes is depicted in the Bakemono E (化物絵) drawn by Kōhōgen Motonobu is one by the name of "otoron.

"[3] Concerning the change in names such as "otoroshi" and "odoro odoro," the yōkai researcher Katsumi Tada posits that in the "Bakemonozukushi," the name written was actually "orodoku" (おどろく, to surprise) with the final く (ku) written very long (refer to image), so "otoroshi" (おとろし) could simply be a misreading of this.

[1][2] In yōkai-related literature and children's illustrated yōkai reference books starting in the Shōwa and Heisei periods, it is often explained that when they find people who do imprudent or mischievous things at shrines, they would suddenly come falling from above.

[8] Kenji Murakami did not find any legends that followed this explanatory text and posits that this is nothing more than a made-up imagination based on Sekien's otoroshi picture in the Gazu Hyakki Yagyō (where it perches atop a torii).

[2] While it is unknown what relation this may have with the otoroshi in yōkai pictures, in Yuki no Idewaji (雪の出羽路) (1814) by Edo Period traveler Sugae Masumi, there is the following story about a hill road: If you pass by the Sae no Kamizaka at evening among other times in a leisurely stroll with a light drizzle and thick clouds, there would be a man who meets with a woman, the woman would meet with the man, and nurarihyon, otoroshi, nozuchi, among others would go on a hyakki yagyō, so some call it the bakemonozaka (monster hill).

[10] Also, in the public archives of Akita Prefecture, there is a nikuhitsu book titled Kubota Jōka Hyakumonogatari thought to be created by a warrior of the Akita Domain (author and year unknown), there is a depiction of a human-like yōkai with a huge head called the "Naganozaka Hiyama Yashiki no Odoroshi" as one of the yōkai called forth by the hitotsume-kozō.