From publisher blurb:
In honor of the 2020 Asian Lunar New Year, Skirmisher Publishing is proud to announce the release of “Jinshu Shu, the Metal Rat: A Monster for 5th Edition”!
Jinshu Shu are elemental creatures that look like rats made from various sorts of precious metal and which are created on the Elemental Plane of Earth through a convergence of metallurgic, metaphysical, and elemental fire and air energies. They are very adaptable and might be found almost anywhere on the Prime Material Plane, although given the choice they are most likely to inhabit places where they can find their favorite foods, to include gardens, forests, and graveyards. They also sometimes dwell in the temples of various deities, especially those associated with treasure, craftsmen, death, and the element of Earth, where they typically serve as companion animals or guardians.
This title includes a detailed description for the Metal Rat, stat blocks for both individual monsters of this sort and swarms of them, and special variant rules affecting the conjuration of such creatures.