Cerebos explains.

"What I want," he says, licking his chops, "is what all creatures want. To run free, to dominate, and to fill all the females with my spawn, so that they will spread and breed and thrive. Then, we will return to my home and teach my former master who is the true lapdog."

"And what does this have to do with me?" You ask, terrified of the answer.

"Well," comes the growling response, "my spawn need mothers, and what better breeders are there but humans? Your kind puts rodents to shame in sheer breeding ability." Cerebos leans close and looks at you with one massive eye. "You, will spread my spawn for me. We will find fertile females and you fill their bellies with my pups."

"No. No, I refuse!" You scream at him.

"You have ****!" Cerebos snaps, clamping his jaws at your head. "When you gave in to your instincts, you gave up your humanity. You're my pet now and you will do as commanded! Now...BRING ME FOOD!"

Your ears ring painfully. You try to resist, but you feel compelled to obey. You grab your wallet, run out to your car and start driving. Looking out the window, you can see Cerebos keeping pace with you easily with long, loping strides.