https://twitter.com/glasspetalsmoke/status/1397196870913515520

I've not often seen (yet?) suggestions of using bestiaries as mnemonic techniques, but here's one in Charles Butler's Oratoriae Libri Duo.

What other sources used them this way before or after?

To be clear I'm aware of their use for such, but just haven't read much about them in this period for this particular purpose in these settings.

This would seem to be the sort of ancestor of the bestiary that might be used as a mnemonic tool, but given it's 1658 publication date, it's likely the case that this would have been too late for it to have served this purpose for most (without prior knowledge).

Apparently the Encyclopaedia Britannica labeled it as “the first children’s picture book.”

A Medieval term

The bestiary, or "book of beasts", is more than just an expansion of the Physiologus, though the two have much in common. The bestiary also describes a beast and uses that description as a basis for an allegorical teaching, but by including text from other sources it goes further; and while still not a "zoology textbook", it is not only a religious text, but also a description of the world as it was known.

The bestiary manuscripts were usually illustrated, sometimes lavishly, as for example in the Harley Bestiary and the Aberdeen Bestiary; the pictures served as a "visual language" for the illiterate public, who knew the stories - preachers used them in sermons - and would remember the moral teaching when they saw the beast depicted. Bestiary images could be found everywhere.