The Beast of RR is the presence of the desire to satisfy the old appetite within a NON-inebriated addicted drinker. Once IT got YOU to drink, the Beast of RR evaporated, only to re-condense upon your returning to your right mind.
Drunken behavior is, of course, very beastly, but that's not the Beast driving the AV.
From reading the lyrics, it seems he's writing about both concepts of beast.