http://www.psychologytoday.com/blog/brainsnacks/201203/the-only-five-basic-fears-we-all-live
Research into the basic psychology of fear, in this article on Psychology Today, Karl Albrecht expresses his ideas that there are only 5 natural fears.
Death (Heights, or the ocean)
Pain or Mutilation (The fear of insect, bugs or anything poisonous that could affect the human condition)
Loss of Autonomy (Being trapped, enveloped, imprisoned, can be applied both the the body, and to relationships or social standing)
Seperation (Abandonment, Isolation)
Humiliation or "Ego Death" (Personal Worth)
According to him any other fears can be applied to these over arching categories.
I can use these basic ideas to influence parts of character designs, such as the fear of abandonment could include a creature with no mouth, tortured and unable to speak. Or a creature with a severely limited range of movement, for the lack of autonomy.