What is the origin of this weird looking facial feature/mask? I have seen this in one or two animes (plural of anime?) where characters have long cylindrical protruding mouths. It is quite rare(?) as I had seen this in only a handful of anime shows (I don't know the names). The recent ones that I know is Haganezuka and Kozo Kanamori from Demon Slayer (the blacksmiths/sword makers who made swords for Tanjiro and Inosuke).

The other one that I remember is a fishmonger in Ninja Hattori (a show (is it an anime?) I used to watch in my childhood days) and it is always the fishmongers and shopkeepers. I don't remember any main characters or any characters noteworthy. First of all, that feature is not possible biologically/in real life. So, why is it adopted in anime and cartoon shows? What is it called (if it is a trope)? What is the origin of this feature? Are there any characters noteworthy having this weird facial feature/wears this mask?

I found this picture after a little bit more searching:

It said &quot;O-face (octopus like face)&quot;. Searching for &quot;octopus like face&quot; yielded me no results. I do know about O-face which is ahegao (NSFW). But I don't think this applies here.

It is not the pout face or the side faced lips expression (I don't know the exact name either(?)). Below is Suneo from Doraemon.
The face on the first picture comes from Hyottoko, which according to wikipedia is:

a comical Japanese character, portrayed through the use of a mask. His mouth is puckered and skewed to one side. Some masks have different eye sizes between the left and right eyes. He is often wearing a scarf around his head (usually white with blue dots).

The reason for it to be commonly used extends beyond anime and manga, though, as it is a common stock character in other media — such as theater — too:

Hyottoko seems to have been a legendary character in Japan in the past, and is now a stock character.

The reason why its features are the way they are, albeit exaggerated, is explained by its name too:

The origin of the name comes from &quot;fire&quot; (火, hi) and &quot;man&quot; (男, otoko), because the character is blowing fire with a bamboo pipe, hence the shape of the mouth.


I don't think Suneo's expression is supposed to be an adaptation of the mask or what it tries to convey, though I don't have anything to back that up with.