Uwan is a yokai who loudly says its own name (like a pokemon) with a disembodied voice, causing people to lose sleep. Teeth blackening was popular among noblemen and the warrior class in medieval Japan, so his black teeth may signify that he was originally one of them. From: Bakemono No E, 18th century
The Hellmouth is an entrance to hell that manifests as the open jaws of an infernal beast. Depictions of Hellmouths were common during the Middle Ages and Renaissance in manuscripts, and even as dramatic mechanical set pieces in theatrical productions.
Image sources:
The Monster of Krakow first appeared in Histoires Prodigieuses by Pierre Boaistuau, 1559. Four hours after its birth, the demonic beast reportedly uttered “Watch, the Lord cometh” and died. Source: Wellcome Collection
Initial Letters from “The Discouerie of Witchcraft..” by Reginald Scot, 1584. Source: Wellcome Library
Full title of book: “The discouerie of witchcraft, wherein the lewde dealing of witches and witchmongers is notablie detected, the knauerie of coniurors, the impietie of inchantors, the follie of soothsaiers, the impudent falshood of cousenors, the infidelitie of atheists, the pestilent practices of Pythonists, the curiositie of figurecasters, the vanitie of dreamers, the beggerlie art of Alcumystrie, the abhomination of idolatrie, the horrible art of poisoning, the vertue and power of naturall magike, and all the conueiances of legierdemaine and iuggling are deciphered. And many other things opened, which have long lien hidden, howbeit verie necessarie to be knowne. : Heerevnto is added a treatise vpon the nature and substance of spirits and diuels” Source: Wellcome Library
