Apep was the Egyptian god of chaos and the greatest enemy of the Sun god Ra. This god appeared as a giant snake and was much feared by Egyptians, even in their death—as he’s known to eat souls. To ward off Apep, they would defile effigies and bury the dead with protective spells.
Frasmiel is a demon who appears as a giant serpent with a human head. He’s a subordinate of the prince Uriel and infernal duke who commands 650 lesser demons. He’s known for being particularly evil and dishonest, like the other dukes who serve under Uriel.
Nure-onna (“wet woman”) is a yokai found in rivers and the ocean. It helps a fellow water monster, the ushi-oni, to hunt humans. It hands the victim a baby that turns into a heavy rock, pulling them into the water where the ushi-oni devours them. Image: Toriyama Sekien, 1776 & Sawaki Suushi, 1737