Hen's
Examples
They only lay one egg which is white, the size of a halfpenny roll, by the side of which they place a white stone the size of a hen's egg.
He jumps up on the hen's backs without so much as a with your leave or by your leave.
The thing is, he's too distracted to notice it, but while Hen's been looking for all the answers, something mind-blowing happened: He got a life.