A few years back a friend of my wife found an egg laying out in the open in a local park, so rather than let it get eaten by dogs or whatever, he took it home and hatched it. He bred chooks, so had all the gear. It hatched out, and when it was a ball of fluff, a couple of days old, he gave it to us, to see if our pet duck would adopt it. Well they got on pretty well, but the duckling adopted me a a parent figure. It use to follow me around the yard everywhere, and even got under the car with me, when I was working on it. That was a bit of a problem, because you had to make sure you didn't squash it when you moved around.
It used to wander around yard with the chooks and "Quack Quack" during the day, and slept with "Quack Quack" of a night in her separate pen. As it got older, it started to follow me around less and less, and was getting harder to approach each day. Eventually it was fully fledged, and turned out to be a beautiful little male wood duck. Then one morning I came out and he was gone. The pen he slept in had no top on it, and he could easily jump the side, when he wanted to get out. So I hope he just suddenly decided it was time to go and be a wild duck again.
A couple of crappy pics from my old phone camera.