We recently acquired a flock of hens with a bonus duck. The person we bought the chickens from also had ducks which he had previously sold. Days after the ducks were gone he saw a strange looking chick peeking out from under a broody hen. Apparently the hen had sat on a duck egg and (quack!) a duck was born. Just like in the stories he bonded with his hen momma. When asked if we wanted him/her along with the chickens we of course said yes (we seem to say yes a lot).
He came to us known simply as “Duck”. We thought him particularly dashing and thus in need of a name with appropriate dignity. Behold Arthur.