Beastclad Butcher is a boss in BLACKSOULS 2 you can find in the Slaughterhouse, defeating him will lead you to the Carroll River area. You can summon the dream spirits Musicians of Bremen to help you in the fight.
After going through the fog the Butcher won’t attack you right away, he will start talking about love and about a certain someone who taught him the importance of emotions. And then he will start talking about the song of Jubjub, saying how Bellman recited it thrice.
Shortly after that, the fight with him will start – he will get mad. During the fight, he mentions the Beaver a lot. His dialogue is related to The Hunting of the Snark poem written by Lewis Carroll.
Killing him will give you the Soul of the Butcher, and the Butcher’s Ring.