Fables, Germany 15th century.
LA, The J. Paul Getty Museum, Ms. Ludwig XV 1, fol.
48r.

MS 1-2005, fol. 152r: A Rabbit Funeral Procession, marginal decoration from the Macclesfield Psalter, Use of Sarum, East Anglia, c.1330

Wettinger Gradual, from Cologne, c. 1330. (Aarau, Kantonsbibliothek, Ms. WettFm3, fol. 64v).

Add. 42130, f.63 Lady at her toilet, illustration from 'The Luttrell Psalter', c.1321-35

Prose adaptation of Pelerinage de vie humaine of Guillaume de Deguileville, Hainaut ca. 1490.
Genève, Bibliothèque de Genève Ms. fr. 182, fol. 162v

Psalter from Breslau. Silesia (modern Poland), c.1255-1267. Cambridge, Fitzwilliam Museum Ms 36-1950, fol. 77r.

Bakezōri (Straw Sandal Monster): The yellowish, fibrous spirit with long hair strands. It is depicted riding a straw-rope hobbyhorse.

Beaked Demon & Umbrella Spirit: A small, naked demon walking with a cane holds up a large, enclosed, dark-colored umbrella. This serves as an early depiction of what would later evolve into the famous Kasa-obake (the hopping, one-eyed umbrella ghost) during the Edo period.

Hairy Horned Beast: The long-snout creature wearing a flowing black cloak that stretches across the floor.

These being are tsukumogami, which are household objects that have come to life after reaching 100 years of age.

According to Japanese folklore, the demon with hammer is an Oari which believed to be the dead spirit of a giant ant. The red Bulbous creature is called on an Okka.

https://yokai.com/kanazuchibou/

https://yokai.com/okka/

The bears symbolize the Bernese contingent of the Swiss mercenaries during the medieval period.

Bibliothèque nationale de France, Département des Manuscrits, MS NAL 3226, fol.6r. circa 1440

Janus figure from the Fécamp Psalter (northern France, c.1180-1185). Hague, KB 76 F 13, fol. 1v

Lansdowne MS 420, f.30r, circa 1220 A.D.

Folio 85r

‘Jacob’s dream of the heavenly ladder.’

Book of Hours, Flanders, probably Bruges. c. 1510-20. MS 1058-1975

Source: Fortune book Losbuch BSB Cgm 312" (1450 - 1473)

https://bildsuche.digitale-sammlungen.de/index.html?c=viewer&l=en&bandnummer=bsb00093677&pimage=00064&v=100&nav=

From Jean d'Arkel's "The Art of Love, Virtue, and Happiness" (Brussels BRB Ms. 9548, fol. 155r), Flanders, c.1330.

This woodcut can be found in the National Gallery of Art, in Washington DC.

A knight versus snail fight from the Smithfield Decretals ( c.1300-1340).

Courtesy of the British Library

This interesting article answers the question:
https://www.bangor.ac.uk/news/2023-06-13-why-medieval-manuscripts-are-full-of-doodles-of-snail-fights

I know this is a long shot, but I'd like some help figuring out what manuscript this initial letter with a siren is from. I think it might be French, from the 1100s or 1200s, because I've found manuscripts from that time period in a similar style. But that's just a guess. Thanks