Sweetheart was the name given to a 5.1 m (17 ft) male saltwater crocodile which Northern Territory folk legend claims was responsible for a series of attacks on boats in Australia in the 1970s.

Sweetheart first rose to prominence around 1974 and was dubbed by locals as the "heavyweight champion" of Sweets Billabong - where he gets his name - in the Northern Territory's Finniss River, south west of Darwin.^[1] He frequently attacked outboard motors, dinghies, and fishing boats, but there is no known case of his attacking humans.^[2] In July, 1979 Sweetheart was finally caught alive by a team from the Territory Parks and Wildlife Commission due to fears for human safety, but died while being transported when he became tangled with a log.^[3] The cause of death was later attributed to a slow drowning, probably due to being tranquilised with the sedative Flaxedil.^[4]

The crocodile's mounted body was prepared for an Australian tour by Ian Archibald^[4] and eventually placed on permanent display at the Museum and Art Gallery of the Northern Territory.^[5] The story of Sweetheart was interpreted with considerable artistic licence by filmmaker Greg McLean in his 2007 creature feature Rogue, starring Michael Vartan, Sam Worthington and Radha Mitchell.^[6] Sweetheart's dimensions were expanded by two metres in the film, which saw Academy Award-winning creature designer John Cox^[7] win an AFI Award for his construction of the crocodile used on screen.^[8]