A farmer bought some ducks and added them to his own, brace of ducks, flock of ducks, flush of ducks, paddling of ducks, raft of ducks, team of ducks, as you wish.
Anyway, after a couple of weeks he noticed one duck wasn't joining in the ducky games, and never went near the water. Closer inspection revealed this duck had chicken feet.
I suspect, the webs just didn't grow for some reason.
So, is this a ducken or a chuck?