It was intended to be a sequel to Benicio Del Toro's The Wolfman (2010). It was changed because Universal decided not to continue with their original vision for their classic monsters revival.
The bolt action rifle used by some of the hunters is a Mosin Nagant. These were first produced in Imperial Russia from 1891 until the 1940s by the USSR and were also used in limited numbers by other Eastern European nations (including Finland). This places the time period of this film sometime after 1891.
Filmed at the same time as Kevin Costner's Hatfields & McCoys (2012) at Castel Film Studios in Romania.
No animals were harmed or mistreated in the making of this picture.