It bursts forth from your nether regions or stomach in a memorable way that may just be the start of your own personal franchise.
It uses the tried and true brainwashing methods of sleep-deprivation and other intense psychological manipulations designed to break down the autonomy of the individual, usually quite successfully.

You have no basis of communication with it, and yet you are under its control.
You feed it when it's hungry, clean it's bodily wastes, attempt to appease it when it is unhappy.
When it smiles or is happy you will echo the emotion, when it's unhappy you will feel sad.
Everything you do will have the allowance for the well-being of the creature built in. You won't go on holiday, change jobs, or even think about going to the movies or renting a DVD without due consideration to what will work within the constraints of your new master/slave relationship.
If it allows you just one extra hour of sleep, you will be pathetically grateful to it.
This is your baby, and you
will obey it.