Failure?

Melissa whimpers as she feels Beast's cock throb with her, his evil seed filling her womb. Your cock slips from her mouth as she tries, yet again without success, to pull herself from Beast and the cum that will define her further existence. You cum at that moment, an instant too late for the hellhound to be, coating her face and chest with your dark seed.

Beast can sense the change within Melissa and pushes her back to her hands and knees licks at the pussy of his mate to be.

As Melissa squirms in front of Beast, her feet lengthen as paws form at the base and her legs shift into a digitigrade form. Her pussy shifts to a form that better accommodates a canine dick, and Melissa stops struggling as pleasure overtakes her fear.

You kneel before her, looking into her eyes as her intelligence fades.

"Almost gone," you say as the emerging hellhound nuzzles at your hand with her growing muzzle.

"Bitch," you name your creation.

You move to pet the top of Bitch's head and feel her ears follow, becoming pointed and settling into a wolflike position. Her breasts recede into her torso as additional nipples erupt below. Finally Bitch howls into the waning night as her body is covered in a furry pelt and a double cocked tail grows from her backside.

"Good, Bitch," you say.

Bitch presents herself to Beast, and the pair of hellhounds return to fucking.