Norseman, the damned things exist. I've been face-to-face with an eight and a half foot tall male wondering whether or not it was going to take my head off first, or my friend's, or my brother's. But telling you that's not good enough.
Now, I wasn't a scientist then, but I am now. A bonafide state-licensed, professional chemical engineer. I'm also a West Point Graduate, served on the faculty there, commanded troops, and served on high level staffs. I could go on. But I'll tell you. None of that's good enough. There'll always be some fool more interested in analyzing how I might have been honestly mistaken than in what I actually saw. The fool will eventually demand proof that I wasn't mistaken. Well I can't see one for him and I don't have a body, so he walks away convinced I'm mistaken despite my reputation and credentials. Why should I bother?
Eventually the fool may see one for himself, stop bothering me, and share my frustration when he reports his experience.
And eventually someone will drag in a body and that will be both the end and the beginning of it.
In the meantime, after you get past proving to yourself they exist, I'll be here for you.