They are photoshopped.

Repeating details along the shaft are a dead giveaway...


What strikes me as odd is the amateurish quality of all these fake giant dick pictures.

I could easily fake a picture of a giant dick that would be nearly impossible to identify as a fake... all it takes is a little more time with photoshop to nuance out the repeating details, clean up edges, ad the right kind of noise in the right areas.