[lomax]

I've found another interesting explanation from Dr Rampa about elementals and thoughtforms.

''But let us return to our “elementals.” What do we mean by
elementals? Well, elementals are a primary form of spirit life.
They are a stage up from thought forms. These thought forms are
merely projections from the conscious or unconscious mind of the
human and they have merely a pseudo life of their own. Thought
forms were created by the ancient Egyptian priests in order that
the mummified bodies of great pharaohs and famous queens
could be protected from those who would desecrate the ancient
tombs. Thought forms are constructed with the idea that they shall
repel invaders, that they shall attack by impinging upon the consciousness
of those who would intrude, and, in impinging upon the
consciousness, to cause such extreme terror that the would-be
burglar flees. We are not concerned with thought forms, for they
are mindless entities which are merely charged by long-dead
priests and set to accomplish certain tasks, the guarding of tombs
against invaders. We are concerned for the moment with elementals.

Elementals, as we have stated, are spirit people in the early
stages of development. In the spirit world, the astral world, they
correspond roughly to the position occupied by monkeys in the
human world. Monkeys are irresponsible, mischievous, frequently
spiteful and vicious, and they have no great reasoning power of
their own. They are, as one might say just animated lumps of
protoplasm. Elementals, occupying about the same status in the
astral world as monkeys in the human world, are forms which
move about more or less without purpose, they jibber and put on
strange horrifying expressions, they make threatening motions
at an astral traveling human, but, of course, they can do no harm.
Always keep that in mind; they can do no harm.
If you have ever been so unfortunate as to go to a mental
hospital and see really bad cases of mental derangement, you will
have been shocked at the manner in which some of the worst cases
there come up to one and make threatening, or possibly meaningless,
gestures. They slobber and drool, but if they are faced with
determination they, being of a very inferior mentality, always
retreat.

When you move through the lower astral planes you may meet
some of these people, some of these strange, outlandish creatures.
Sometimes if a traveler is timid these creatures cluster around and
try to fluster one. There is no harm in that, they are quite harmless,
really, unless one is afraid of them. When one is starting astral
travel you will often get two or three of these lower entities congregating
nearby to see how one “makes out”, in much the same way
as a certain type of person always likes to look at a learner driver
taking a car out for the first time. The spectators always hope that
something gory or exciting will happen, and sometimes if the
learner driver is flustered he, or, more usually, she, will collide
with a lamp post or something else to the great delight of the
spectators. The spectators, as such, mean no harm, they are just
sensationalists trying to get a cheap thrill. So with the elementals
they are merely out for cheap entertainment. They like to see the
discomfiture of humans, therefore, if you show any fear, these
elementals will be delighted and will keep up their gesticulations,
their fierce and threatening approaches. Actually, they can do
nothing whatever to any human, they are more like dogs who can
bark only, and a barking dog does no harm. Furthermore, they
can only annoy you so long as you, through your fear, permit
them to.''