I love this. The colors are great and those strokes give a really nice texture to the whole piece. The water is simple, but it works.
I'm not sure if it was your intent, but Gabumon here looks more like the pelt he wears is part of his body. It could be remedied by defining a difference between his body and the pelt, such as having his flesh visible through the eye-holes on the pelt (I remember a couple of scenes in the anime with this) and having the actual muzzle visible underneath the pelt muzzle. Due to the muzzle's shape and positioning he's looking a lot more dog-like than a reptile. Just some minor nitpickings.
I absolutely love Patamon here and I normally dislike Patamon a lot, so kudos to you.