Scylla was a sea monster of Greek Mythology, most notably mentioned in the Odyssey because Odysseus had to avoid the strait between Italy and Sicily where the monster dwelled.
There are various descriptions of this monster, one more bizarre than the other, but the leitmotif is it having an abnormal number of heads of limbs. What better opportunity to draw again a guy with two heads and four arms?
Imagine him patrolling the straits between islands and kidnapping seamen.