User blog comment:Cory Jaynes/Reapers origins/@comment-1888392-20110803065751

Well, each Reaper looks different. While Sovereign loojed a Reaper Cuttlefish, one looked like a stag beetle. In ME2 inside the Collector Base, EDI suggests Reaper Reproduction is by breaking down species to genetic paste.

Whatever paste they use, the Reaper take on a similar look to like the beings being processed - - thats why the Human Reaper looked human.