Giant hutia
The giant hutias are an extinct group of large rodents known from fossil and subfossil material in the West Indies. One species, "Amblyrhiza inundata", is estimated to have weighed between , big specimens being as large as an American black bear. This is twice as large as the capybara, the largest rodent living today, but still much smaller than "Josephoartigasia monesi", the largest rodent known. These animals were probably used as a food source by aboriginal humans. All giant hutias are in a single family, Heptaxodontidae, which contains no living species; this grouping seems to be paraphyletic and artificial, however.
Traditions and student activities at MIT
"Brass Rat" refers to the MIT class ring, which prominently features the school mascot beaver on the top surface. The ring is traditionally made of gold, the beaver is the largest North American rodent, hence "gold beaver" has informally become "Brass Rat" in student lingo.