I've seen faux caviar passed of as genuine caviar and many experts seem to actually prefer it in taste tests.

I have also seen surimi lobster tails passed off as real lobster when served sliced and out of shell and particularly when "sauced". Sadly they get away with it and few seem to be able to tell the difference. I have even seen the specific description of "Maine Lobster".

Surimi is the same process as crab sticks and turns cheap and by-product fish into other things and Japan is the main producer....