Giant Merman: King of the Deep
I guess everyone has to have a leader. And in group situations the likes of which Castlevania usually seems to bring about, the biggest guy usually becomes the leader. Armors have a Lord, Skeletons have a guy... even Bats. I guess a Big Merman was overdue, really.
So, there was this meeting see. The Mermen weren't happy with the state of thier rights in the grand scheme of things. They were tired of being treated like 6th string monsters, always the fodder. For once, they wanted to be a later stage enemy, even if that required running the last stage through the sewers... Unmindful of the fact that the Castle Keep would be thrown totally out of wack in comparison to the rest of the castle.
But so it was, the group met, and a leader was elected. He told all the mermen that if they weren't listened to, they would go on strike... Then Dracula and him meet, he's given a bribe, and the union takes a hit.
Seems all that the Ginat Merman needed was a boost in his own ploitical stature, and he'd basically say "fuck you" to teh rest of his people.
I guess you can see where this is going. After his failure to stop one Juste Belmont, the Ginat Merdude was kicked back to the sewers. He tried to make up with his followers... but they just killed and ate him.
The lesson learned? If you screw those smaller than you, at least kill off a good portion of their numbers befoer you come crawling back.