Friend or Foe?

Suppose that one day, someone knocks on your door.  Before you can answer, she slips in and makes herself at home.  She doesn't much like your furniture, so she strings a hammock from one wall to the other and settles in for the night.

While you think this behavior is very strange, she doesn't have a large truck or a bunch of burly guys with her or any obvious weapons, so you let her be.  The first night passes, the morning comes, the sun rises, and all seems to be at peace.

The next night, you start to notice that your uninvited house guest has some funny eating habits.  She is vomiting quite a bit.  Since she is small and delicate, you don't notice any smell or stains on the carpet, so you, in an unusually hospitable moment, let it go.

Another night passes, the morning comes, the sun rises, and life is stranger, but still at peace.  Your new house guest is still vomiting, but despite the fact that no offensive smell or stain comes along with it, you start to notice something even stranger about her.  See, the truth is, you have dozens of uninvited house guests in the house.   And this latest and sweetest new one has a little bit of a mean streak lurking within.   You see... when she vomits, she tends to aim the vomit at one of your other unfortunate house guests.   That, in itself, is just disgusting, but what complicates matters is the fact that the vomit seems to have an exceptional ability to dissolve skin and flesh.   This, you notice, as one of your other houseguests goes from his healthy, happy self to nothing but scant, liquefied remains.

This is awful.  Horrible,  Gross.  Surely, you must now call the police or at the very least, throw this houseguest and her hammock out the door.  Good Riddance.

But then, as all rated R, low budget horror movies would dictate, the situation worsens before your very eyes.   Before you can excuse your guest to the great outdoors, she does the unthinkable.  She turns, grins, and eats those gross, liquefied remains.

Yet, still you debate.  Should I throw her out?  Should I just let her be?   Because, you see, in the middle of her feeding frenzy, she winked at you and promised you two things.  One:   she promises she will never come after you.  Two: she promises she will hunt and eliminate only those houseguests that are truly annoying you.

Thus, you ponder.   Keep her?  Kick her out?  Friend?  Foe?
What's your choice?

And, do you let her keep that pesky hammock strung between the walls?