So the Strawhats went from Heaven to Hell, huh?
I guess Chopper knows this Doctor Hogback because he's infamous among physicians for doing strange experiments? The Kerberos, the Kentauros, Hildon and that other two things kinda do look like experiments went wrong.
Hey… wasn't Dr. Chirurg (aka Hiluluk) from the west? West as in "West Blue"?
Also: Note how Hildon says "ドクトル" in contrast to the usual "ドクター"-pronounciation for "Doctor". Sounds more like the German/supposed Transsylvanian (?) pronounciation to me.