There usually comes a point in dreaming when we must face our worst fears. When lucid dreaming, this can be so shocking that we believe in the particular monster and usually wake from the dream immediately. However real the horror may appear at the time, it remains a dream, and this understanding is usually enough to dispel any fear. But sometimes the dreamer is not so convinced when facing down a twenty-foot demonic presence. At such times the thought goes through anyone's head that perhaps they have entered some hellish separate reality, a parallel realm in which one can really get hurt.
The principle to understand with all such apparitions is the simple equation that their substantiality is in direct proportion to your belief. So first of all remember that it is a dream image and probably some unacceptable aspect of yourself. Love, laughter and light seem to be the best weapons against such entities. Keeping a sense of humor in a dream is perhaps the most precious talisman you can possibly take with you to the other realm. But the same could be said for the waking world as well. Loving the beast is another strategy often tried by dreamers. Embracing the monster and accepting it usually brings an immense sense of relief, as if you have been repressing a part of yourself and creating your own Minotaur in the center of your private labyrinth. Often it is reported by lucid dreamers that in embracing the monster the dreamer discovers the unacceptable part of themselves. Talk to it, asking it who it is its name is often revealing. Ask it why it is trying to threaten you or what it is trying to do and how you can help it.
A nudge in the right direction can yield real insights. Summoning your favorite person, your worst enemy or a wise old man or woman, can reveal unexpected delights of real wisdom, humor and compassion. If you can remember in the midst of all this activity to do a reality check on whomever you have summoned or intended, you will be able to discern revealing differences between the original and your dream replica.
~from Maat's Book of Shadows