However, this fan notes that although it appears the other prisoner was fed to the Demogorgon, we never actually see what happens to them.
The user began: “Let’s put aside guessing who’s ‘The American’, and look at what Russians do to the other prisoner.
“Almost everyone (including me) assumed they fed the Demogorgon with him. But we don’t see that actually happening. That’s because it wouldn’t make sense.
“In season 1 demogorgon hunts a deer, in season 2 Dart eats Dustin’s cat.
source: express.co.uk