The Moke has a few abilities and things that it is used for, most well-known is it that while it can reach up to 10 inches, it is able to shrink at will, which is the reason that no Muggle has ever seen it. It also has its uses - the skin is actually widely used to make Mokeskin bags and purses. When approaching a stranger, this bag would shrink, making it pretty much impossible for the stranger to find it. This also means that if the owner put something in the bag, only the owner could take it out.
The Moke would most likely be a great pet for those who like lizards, whether they are magical or not. The Moke does not seem to be much different than the muggle lizard that many of us might now, except for the fact that it is able to shrink. It's diet and living criterias is much the same. Therefore, the Moke would be a great pet for those who enjoy reptiles, and are willing to put in the work as reptiles are no easy pets to hold. If wishing to give such a pet to ones child, it might be good to know that the parents should be part of the decision too, as it can be a great responsibility for the child. For those kind of pet owners, the later use of the Moke might be great for profit or own benefit, especially if one tends to get their money stolen.