Kami, Kanazuchibō
Selection from Bakemono Zukushi, accessed at Public Domain Review here
[It's been a long time since I've made a yokai. The kanazuchibō and/or daichiuchi is one of many yokai that was created by illustrators as opposed to having a folkloric origin, so there's no real consistent story about what they are and what they do. So my inspiration here was equal parts The Shoemaker and the Elves and Forged in Fire. In fact, it was repeated references in that show to "forge gods" by competitors that inspired @abominationimperatrix and I to do some brainstorming about what might fit the role of a localized, capricious forge spirit, and this is the result.]
Kami, Kanazuchibō CR 3 CN Outsider (native) This little humanoid is noticeably muscular, with oversized arms carrying an oversized hammer. Its head is like that of a hawk, with bulging eyes and a hooked beak.
The kanazuchibō are sometimes referred to as “forge spirits” or “forge gods”. They are kami of metalworking, and occupy smithies in order to watch and meddle with those working there. They do not care for what purpose the weapons, armor, horseshoes or other metal items made are used for; they only care about the quality of the craft itself. Kanazuchibō are fickle creatures, and may use magic to assist or hinder the smith using their forge as they see fit. They are also timid—with their incredible stealth and ability to merge with their smithy, a kanazuchibō is rarely seen unless they choose.
A kanazuchibō will pursue its own projects in a forge when mortals are off duty, particularly at night. The proprietors will find that raw metal is mysteriously transformed into finished goods, often of particularly high quality. The kanazuchibō do not mind if these are sold off, but do not react kindly if a work in progress is tampered with. Kanazuchibō in a smithy can be befriended by those working there, but this is a slow process, and the forge spirits are easily offended. They are more likely to befriend knowledgeable smiths, as they have a great appreciation of the technical details of working with steel. If the kanazuchibō are allied with, they may assist forging directly by acting as strikers, and defend the forge and its workers from physical violence.
Kanazuchibō prefer not to fight, instead repelling hostile creatures with supernatural fear. That said, the kanazuchibō are very strong for their size, and their sledgehammers can be used as lethal weapons as well as crafting tools. They use hit and run tactics, relying on their stealth and ability to merge with their wards to frustrate and discourage anyone looking for a straight forward battle. Kanazuchibō will only fight to the death to prevent their smithy from being permanently destroyed. Otherwise, if badly injured, they will merge with their wards to hide and heal.
A kanazuchibō stands about 2 feet tall; they often carry hammers longer than they are tall. Despite their height, they are very dense, weighing as much as 150 pounds.