One of the witches describes Ethan as "Lupus Dei." This is Latin and roughly translates as Wolf God or Wolf of God
Penny Dreadful's Production Designer Jonathan McKinstry said the script envisioned Evelyn Poole's mansion as 'a cross between Antoni Gaudi and H.R. Giger'. The Parlour's skeletal decor takes inspiration from the Sedlec Ossuary, just outside of Prague.