Bigfoot? I don't know about this - sorry Holls - I think it's a cool thing if it does exist.
Loch Ness/Lake Monsters? I think so, maybe moreso than Bigfoot even. Though if they exist than Bigfoot may as well. I have seen some weird looking fish that have come out of the water. Almost prehistoric looking, so why not lake monsters/Nessie?
Aliens? My sister swears by them. I'd like to believe her. She is kind of nuts. I tend to think they do exist and it's just a matter of time before we see real proof.
Vampires? I think that there is a group of humans who drink blood but not as a necessity to live. They do it because they like it and romanticize the whole vampire lifestyle. They also don't live for hundreds of years. Maybe many, many years ago they really did exist though.
Werewolves? Not really. Up there with Bigfoot.
Mothman? Yeppers. Totally buy into this one. I think the Mothman gets a really bad rap though. I think he is a messenger to catastrophies and maybe doesn't quite know how to communicate with humans.