Wikipedia: The Water monitor, (Varanus salvator) is a large species of monitor lizard capable of growing to 3.21 metres (10.5 ft) in length, with the average size of most adults at 1.5 metres (4.9 ft) long. Maximum weight of Varanus salvator can be over 25 kilograms (55 lb), but most are half that size. Their body is muscular with a long, powerful, laterally compressed tail. Water monitors are one of the most common monitor lizards found throughout Asia, and range from Sri Lanka, India, Indochina, the Malay Peninsula and various islands of Indonesia, living in areas close to water.
Wikipedia:Water monitors can be defensive, using their tail, claws, and jaws when fighting. They are excellent swimmers, using the raised fin located on their tails to steer through water. Water Monitors are carnivores, and have a wide range of foods. They are known to eat fish, frogs, rodents, birds, crabs, and snakes.They have also been known to eat turtles, as well as young crocodiles and crocodile eggs Like the Komodo Dragon, they will often eat carrion.
It is a reptile i had found in water in my province