Does my Mole on the Back of My Ear Look Cancerous? (photo)

I would highly encourage you to see a plastic surgeon or dermatologist to have the lesion evaluated and most likely biopsied.  

Consult a plastic surgeon for removal and submitting for pathology. Moles should be removed full thickness by excision to be able to examine properly

Because your mole is dark and irregular and is in a sun exposed area, it is important for you to have it examined and most likely biopsied. However, I fully disagree with the plastic surgeon below who frequently states that you need a complete excision with sutures and even says that you need to see a plastic surgeon only! The shave biopsy/removal technique is the predominant procedure used by dermatologists to remove flat hyper pigmented areas such as yours on the ear. This technique produces a good cosmetic outcome and, if done well, produces an ideal specimen for histopathologic evaluation (which is also contrary to what is stated below). There are numerous references from other physicians who have reached the same conclusion. Here is one example of an article just published by a well respected dermatologist: Practical advice regarding problematic pigmented lesions; Dirk Elston, Journal of the American Academy of Dermatology, July 2012, Volume 67, Number 1, pages 148-155. In his article he specifically states "Saucerization with a narrow margin of normal-appearing skin produces an excellent diagnostic specimen with minimal functional impairment and good cosmetic outcome. This is my preferred technique." You can follow the video link below to learn more about identifying the changes in moles that are suspicious for skin cancer.