Told by Peter York.
A long time ago the Rat had the Beaver’s tail, and the Beaver the Rat’s
tail. The Rat wanted to trade tails, very badly, but the Beaver didn’t
care enough about trading, but at last he traded. Then the Beaver when
he got his present tail liked it very much for he found that he could
swim faster, but the Rat didn’t like it, because he had to swim slower,
so he begged the Beaver to trade back, but the Beaver would not trade;
so the Rat cried and cried till his eyes got small, and this is the
reason that the Rat has small eyes and a small tail.
(Rat here means the Muskrat.)