Metal armor. Chop-shopped bathtub.
A bathtub with one short side removed, turned upside down and crudely fastened onto a pony’s back. Effectively metal armor, but lacking any sophisticated design is very hindering.
Metal armor 20 AC, -3 Agi, DT 8
“Another result of the pre-war eras desire for everlasting things, is the common bathtub. Often constructed from material similar to what was used in the construction of the vaults exterior walls, these tools of basic civility are remarkably hardy.”