From The Sexxxy Files

Meet Varanus Lirungensis, the most recently discovered species of Indonesian Water Monitor. The person is holding it like that because they are extremely bitey. They stay bitey too, and the ones you see in the pet stores can grow to a good 7 feet or more. Typically, they are bought by kids as babies due to their bright color patterns, and later flushed by parents when they start growing. If you must have a monitor, get a Savannah (big, but easy to tame and easy to keep) or a roughie, which are gorgeous and very gentle animals.

There are a few places around that breed them, esp. Savannahs, so you won't necessarily be contributing to their reduction in the wild.