The Asian Water Monitor (Varanus salvator), also known as the Common Water Monitor, is a large lizard native to South and Southwest Asia.
Water Monitors are one of the most common monitor lizards found throughout Asia, and range from Sri Lanka and India to Indochina, the Malay Peninsula, and various islands of Indonesia, living in areas close to water.
There are six subspecies of the genus Varanus salvator.

This is the subspecies Varanus salvator macromaculatus, sometimes also called the South-East Asian Water Monitor.

1st, 2nd & 3rd photo: Pasir Ris Park, Singapore, 24 October 2022
4th & 5th photo: Sungei Buloh Wetland Reserve, Singapore, 25 October 2022

See here my short video.