Ok, this post deserves some serious attention.
There's a good reason they are the "lesser kept" monitors. They are aggressive, belligerent, fast, unpredictable, they bite, slash, tail-whip, and make a ton of mess. Not likely that it will see the 5-6 foot mark, most captives mature around 4, but mine was 57", so anything is possible....just make sure you have experience with big mean lizards and crocodiles or you're gonna get pounded by all 6 ends of that thing.
The primary reason that they're a lesser kept species is that most people don't know what they have. It is the exact same thing as how TATF were unknown in the hobby until someone bothered to actually explain what they were, then it turned out that they were more common than vitattus and no one knew what they had.
I agree that these animals are NOT beginner's monitors and command tons of respect. I do, however, strongly disagree with....
Invest in a pair of Welder's Gloves for handling him, and tape the mouth shut and cover it's head with a little cloth bag when you have to work with him. I have been bitten and it's bad - they lock-on and it can last hours if they want it too before they let go. The claws will literally cut into your skin just from it's weight alone and that tail, dude........OMG dude,....the tail, the tail lol Keep a firm grip on that sucker at all times.
He's not going to love you like a Savannah and I have never seen a tame Nile. handle him everyday while he's a juvenile and if you're lucky he might not turn into a chainsaw with legs.
...That nonsense. This is some of the absolute worst advice I've ever seen on varanid husbandry. You take a species of animal known for defensive reactions, and then treat it in such a manner as to guarantee further defensive reactions. This is how you create a large, wild, dangerous animal that is exactly the opposite of what someone assuming the responsibility for a lizard the size of a dog should want. One must build TRUST with the animal; a bond that teaches the animal that you're beneficial and not trying to harm it. Doing what
Frank Castle
suggests will only reinforce to the animal that you're a threat.
If one wants to raise a large monitor into a calm, trusting, tractable pet, reference the video series put out by Kevin McCurly and Jason Raimondi from New England Reptile Distributors (NERD) on socialization and handling. You'll learn a thing or two about the psychology of these surprisingly intelligent animals.
While Niles and ornates both tend to be a bit more wild than a water or albigularis, they are by no means immune to the charms of a competent handler. They don't calm down in a month like the aforementioned species, but with patience and proper husbandry, they make some of the best pets in the big-lizard world. Learn on a savannah, water or a tegu, or hell, a croc monitor, before you try a Nile or ornate. Your life will be much easier.