belphegor (umineko)
One of Umineko no Naku Koro Ni's Seven Stakes of Purgatory, and representative of the deadly sin of sloth. The fourth sister, younger than the three who represent the deadly sins of corrupted love (Lucifer, Leviathan, and Satan) and older than the three who represent the deadly sins of excess love (Mammon, Beelzebub, and Asmodeus). Can be told apart from her similar-looking sisters by her grayish-black hair, kept in a single ponytail.
The human she is based on is Leion.
Named after Belphegor (an Assyrian god made Judeo-Christian demon), who is associated with misanthropy, innovation, and, of course, sloth.