You thought the beaver was a rodent of unusual size? The capybara is twice that big—the biggest rodent on Earth. They can grow up to about 1.3 metres (4.3 feet) long and weighing up to 79 kg (174 pounds).
Its common name is derived from Tupi ka'apiûara, a complex agglutination of kaá (leaf) + píi (slender) + ú (eat) + ara (a suffix for agent nouns), meaning "one who eats slender leaves", or "grass-eater". The scientific name, both hydrochoerus and hydrochaeris, comes from Greek ὕδωρ (hydor "water") and χοῖρος (choiros "pig, hog").
Capybaras are short-haired brownish rodents with blunt snouts, short legs, small ears, and almost no tail. They resemble the cavy and the guinea pig.
The greater capybara is in the same genus as the lesser capybara, but adult proper capybaras tend to weigh much mrore than the lesser capybara. They can weigh up to 200 pounds!
The lesser capybara closely resembles the capybara but adult lesser capybaras typically weigh up to about 62 pounds. This species is reported to be common in Panama, but rare in Venezuela.