They are the original visitors to the planet and are merely biding time until it time to take over. We are serving as a food resource which accounts for mysterious disappearances all over the world aided of course by humanoid robots which are all around us ..oooooooeeeeeeeeooooo. Welcome to the twilight zone
Probably some extraterrestrials long, long ago were on a camping trip and lost their "dog".
Is it even possible? Yes, it is.