Apparition 
To see an apparition in your dream symbolizes your inner essence and personality. It may also represent your ethics and morals.
Ghost
To dream of ghosts typically represents the parts of you that cause you fear. This could deal with some difficult memory or repressed feelings. You could fear death or of dying. Ghosts in dreams can also signify something that you realize you cannot attain anymore, such as a dream that has died. It suggests that you feel cutoff from society in some way. This dream could be urging you to reevaluate the way you think and behave in order to move ahead in life.
To dream that you try to touch a ghost that vanishes suggests that you are working toward dealing with emotions or ideas that you've kept buried, even though you may not be ready to completely address them.
To dream about the ghost of a living relative indicates that someone may try to cause you harm.
To dream of the ghost of a dead friend or relative indicates that you have some shame about a relationship with that dead friend or relative.
Undead
To dream of the undead or zombies implies that you may be being plagued with old sabotaging thoughts. Note the atmosphere of the dream - is it scary or calm? What is the environment? Habits or memories that hurt you may be coming up more often and you could be feeling overwhelmed. This is simply a sign that you are ready to release yourself from these old and nagging thought systems. Seek some help in clearing old patterns.
Fantasy
To dream of a fantasy world suggests a strong desire to get away from your current reality. To be participating in personal fantasy indicates a need to make an important decision in your waking life that may lead to a long held vision becoming a fulfilling reality.
Bogeyman
A popular dream symbol, the Boogeyman either represents your fears or a part of you that you are suppressing something. Many dream theorists advise dreamers to face their Boogeyman and engage it in a conversation the next time they encounter it in a dream. Though scary, this is said to reveal many things about a person and possibly even help them to accept and welcome the suppressed part of them back into their life in some way. Therefore, facing your fears in a dreamstate changes the way you see this fear in waking life.
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