What do you think of this very short story type thing?

It is a free-verse poem, and a good one at that. There is still room for improvement, however. "Curled into pursed smiles" doesn't really make sense, as pursed lips aren't neither curled nor smiling. In your first line, you capitalize Children; in the last line, you don't. You have to either capitalize them both or make the word night in the last line lower-case. "But, those who fear" should not have a comma. You might want to have some of these lines lower-case; they don't all need to be capitalized in a poem. You might want to consider changing "will be spared... For we feed from" so that they are two separate lines (will be spared/We feed). "We come to those who wish" should be "We come to those who wish for". "And to those we appear" should be "And by those to whom we appear, our demeanor will not be forgotten" - but that still doesn't make sense. It should REALLY be "Our demeanor will not be forgotten by those to whom we appear". Should the eyes really be innocent? These Children of the Night don't exactly seem innocent to me. I know that I might seem a bit critical, but I'm only being so thorough because I think that you wrote a good poem and you could make it an even better one. This is a very good start, chillingly descriptive, leaving just enough to the imagination. I really like the line "We are born from the rolling mist that cloaks the ground as thickly as the fear that hangs in the voices of our victims." You should consider taking a course in writing, as you have the mind necessary to create great writing, but you lack the structure. I am not trying to be harsh; I truly hope that my critique is helpful to you. You honestly did a very good job, and I would like to see more from you.