When Georges first meets Freddy, he's in bed and hidden under a sheet. He asks Freddy : "You know my voice ? What's my name ?" and Freddy ironically answers "Belphegor" (a famous TV series in 1968)
When Volpinex leaves with Liz after trying to scare Matthias, Matthias aims at Volpinex with the gun-lighter, pretends to shoot him, and thinks "Out, Belphegor".