So, can they fly with a terribly racistly stereotyped crow's feather? Even I'd buy one in that case!
But seriously, I know nothing about Rats/Mice except that every once in a while, one can lead a circus, be a mighty super hero, wear pants, or cook. Also, some run very fast, and some are very slow. Additionally, sometimes they're very, very violent and befriend dogs to brutally beat up cats. On top of that, I know that depending on who you hear the story from, a rat became a great sensei and became man-like, or a sensei became rat-like. Oh, and all mice are either city mice or country mice that know the secret of the Nymh, befriend some kid and ride in sailboats while trying to get on the family's cat's good side, but in the end, Snowball helped that little girl in All I Want for Christmas. But that security won't last long, since the shrews, mice, badgers, hares, and others are busy defending the abbey from vile weasels, snakes, swallows (only sometimes), or worse.
Clearly, your rat must be the chosen one. What amazing anthropomorphic life will he lead?