A musk-rat.
1624. Martins, Fitches, Musquassus, and diuers other sorts of Vermin.Captain Smith, Virginia, p. 27. (N.E.D.)
1634. Rackoones, Otters, Beavers, Musquashes.W. Wood, New Englands Prospect, p. 88. (Stanford Dict.)
1672. There is a little Beast called a Muskquash, that liveth in small Houses in the Ponds, like Mole Hills, that feed upon there Plants.John Josselyn, New-Englands Rarities, p. 53. (Italics in the original.)
1674. The Musquashes is a small Beast that lives in shallow ponds, where they build them houses of earth and sticks in shape like mole-hills.The same, Voyages to New-England, p. 86. (N.E.D.) (Italics in the original.)
1768. 920 Musquash, 59 Wood Chucks, &c. were slain in the year 1682 as part of an Indian funeral ceremony.Boston News-Letter, June 30: from the Halifax Gazette.
1788. The musquash or castor muschatus, which I have dissected, has no sacs [like those of the American skunk].Dr. S. L. Mitchill in the American Museum, v. 488/1 (May) (1789).
1792. The musquash (castor zibethicus) builds a cabin of sticks and mud in a shallow pond.Jeremy Belknap, New Hampshire, iii. 161.
1834. I took most comfort in catching musquash of anything I used to do.Seba Smith (Major Downing), My Thirty Years Out of the Senate, p. 27 (1860).