7 Largest Crocodiles in History Cassius (17 feet 11 inches) Cassius is a saltwater crocodile from Australia, once recognized by the Guinness World Records in 2011 as the largest crocodile in captivity. Captured in 1987 in the Finnis River in Northern Territory, Australia, Cassius was notorious for attacking boats and becoming a nuisance. He is now housed at Marine Land Melanesia on Green Island. Despite missing a front leg and the tip of his tail due to past battles, he measures an impressive 17