My question is why does the River figure come with a "flesh" mask?
All the figures in that wave come with a flesh mask, though Uncle, the Astronaut and Idris come with masks that go with other characters.
As for why, I have no clue. Character really seems to be obsessed with the whole "Flesh" concept. The Flesh Goo Pond
, the Flesh Bowl Figure Creator
, and now the Flesh masks.