What was the earliest werewolf myth?

Question

So, the earliest werewolf I can find is in Greek times.

But, was there ever an earlier werewolf myth?

Answer 1

There's a wolf transformation in the Epic of Gilgamesh, and as written texts go they don't come any earlier. Although in this case it was a spell cast upon him and he never had a chance to transform back into human form.

There may of course be earlier oral mythology.