Today we have two new conversions of some older edition undead monsters. The swamp marsh dwelling Bog Mummy and the cursed undead priests known as Huecuva (who first appeared in the original Fiend Folio).
Bog Mummy
Wherever a spark of unlife or negative energy touches a corpse naturally preserved by swamp mud, the result is a bog mummy. Bog mummies are always found roaming the place where they arose, and very rarely venture from it.
In the Ivlis Marsh of Barovia, the powerful hag-mother, Baba Lysaga, provides the spark of negative energy needed to create bog mummies. The skin of the bog mummy is leathery, tanned by the mild acid of the peat bog. It is clothed in tattered rags, and the remains of the thongs that bound its hands and the strangling cord that bit deeply into its neck dangle from its body. The monster has incredible strength and its rotting slam attacks are powerful.