Jūbako-Baba - 重箱婆 - (Heavy Lunchbox Hag/Granny.)
• About this yokai: An old tanuki from Tamana district, Kumamoto & Hyūga, Miyazaki prefectures. Disguised as an old lady carrying a heavy looking Jūbako. [Heavy tiered lunchboxes which have a Bento-Box like, new years feast inside (known as Osechi).] Under the guise of an unassuming old woman (who is either too weak to carry the box or too full to finish her meal.) she tricks passerbys into taking the box off her hands saying: "I don't want the feast in this box, do you want a treat or not?" offering them the box. - But, Either the box (or the meal itself) is actually, an absurdly heavy rock in disguise, When they take it, the victim will find themselves carrying an improbably heavy boulder, either falling under the weight or they biting into the appetizing looking meal (only to realize its made of pebbles) far too late. - it's a story that reminds you not to be so eager to accept meals from strangers.
[a simple Jubako & its contents. img source]
• History: It's a fairly common prank shared among henge yokai, particuarly tanuki, to substitute leaves as money, and magically transform stones (or manure.) into food & feed it to unsuspecting humans.
The "Heavy stone" trope is also shared widely between yokai such as: Ubume, Konaki-jjiji, Nure-onna and many, many others.
According to Kumamoto city Museum, Jūbako-baba is a Nopperabo. [A faceless yokai, which Mujina & Tanuki often disguise themselves as.] The Tamana variant of the tale says that she appears on the Hokkezaka Hill which leads towards the castles tower.
The Nichibun yokai database places her description (in the Miyazaki variant) back to folklore journals "能田太郎" from 1935. (earlier stories & variants were passed along orally.) - [Unfortunately, I cannot actually find this version of the story itself online, but i'd assume its the similar to the others but simply set in a different location.]
According to Koorintei Hyosen; Jūbako-baba appears in mountain passes in kumamoto, appearing faceless like a Nopperabo. She has eyes on her legs, from her knee's leading up to her thighs: she scares people with them. (This story is somewhat similar to another nopperabo from Kyoto: Shirime.)