PREDATOR LIKE HUMANOIDS

These refer to cloaked entities, such as the one in the film Predator.
In that film, the protagonists are faced with an invisible creature.  They know it's there because the foliage and branches are moved by its progress through them.  They are referred to as 'cloaked' because they seem to be invisible and may be surrounded by a mantle that makes them so.  The articles to which we are about to link you are courtesy Loren Coleman.

First, a Pennsylvania sighting.

now read on.....  

Second, a video

now read on.....

Third, an opinion on the subject.

now read on.....