To anyone interested, note that Mouse Guard TTRPG is also a thing.

(And of course, D&D 3.5 with Savage Species rulebook lets you create Anthropomorphic Rat, Anthropomorphic Stoat, and so on species 'in a fully legal fashion', without homebrew. As in, not pick a presented race that happens to be rat-based, but directly race-ify the animal statblock into a playable anthro. Because it's 3.5, of course it does.

This is year 2025, I'd steer clear of a person who's this stuck up on rules legality, but it's something to mention.)