Castorino

Italian diminutive of Castoro or Castore (both Italian forms of Castor), formed with the masculine diminutive suffix -ino (itself ultimately from the Latin masculine adjective-forming suffix -īnus "of or pertaining to").

Alongside the word nutria, this is also an ordinary vocabulary word for "nutria, coypu" - a large, crepuscular, semiaquatic rodent variously thought to resemble either a large rat or a small beaver. Native to South America, the nutria was introduced to Europe, Asia and North America due to the value of its fur in Eastern Europe and Central Asia. However, outside these areas, the animal is considered a pest or even an invasive species.