The wren is the symbol of freedom and independency. The dreamer who sees the bird in his dream may wish to escape the daily life and live the life that doesnt take too much of the work. Perhaps the dreamer has a very stressful life, therefore he wishes to become a bird. Alternatively, the wren could indicate the relaxed type of the person, when he is flying through the life easily without any stress.
Read more about dreaming of Wren in other dream meanings interpretations.