Aliens, yes. The galaxy, hell the universe, is too big for just us.
Yeti, yes at one time at least.
Loch ness monster. Maybe at one time something akin to the rumors existed but I don't think it's there anymore if it ever was.
Mothman, dunno, first i've heard of it.
La chupacabra, I think was that coyote-like dog thingy we saw in the news video a while back and rumors ensued about it years before.