Page from the Béatus Manuscript in the Escorial Museum, Spain.

These mostly 11th-century manuscripts are richly-illustrated versions of a famous commentary on the Revelation of St John the Divine
penned by a monk called Béatus (= blest) in the Northern Spanish monastery of Liébana in the 9th century.

On this page an Angel of the Apocalypse is emprisoning in everlasting stocks the conquered Satan,
a sexless figure whose feet and hands nevertheless are curiously similar to those of sheela-na-gigs.

 

Another heliogravure scanned from Zodiaque's splendid "Images de l'Apocalypse",
the Angel of the Apocalypse casts the Whore of Babylon and her gigantic, mis-proportioned horse into the lake of burning sulphur.
The Whore of Babylon is usually depicted nicely clothed, but here she is naked.
There are no snakes, however: that particular trope came a little later.

The illustrator of the Béatus of Burgo de Osma would have had great fun with the (unexpurgated) Brothers Grimm.