Malaysian Water Monitor (Varanus salvator), juvenile. Water monitors can remain under water for up to 30 minutes in search of prey, and are comfortable in both fresh and salt water. They are omnivorous, and in addition to live food will scavenge carrion and garbage. Juveniles may hide in trees. Water monitors can grow to be over 3 metres long, and up to 90kg. Juveniles are more colourful than adults.