Corda

Corda is a sea dragon, ink-black and very big. It only appears out of the sea. A whirlpool would appear out of nowhere, and Corda comes out.

Story
Corda was created by a wizard, named Maleficum. He had created him to get back at every single person who hadn't been nice to him, only Corda was stronger than he'd thought. When Corda killed someone or something, he would only rip out the heart and leave the rest of the body where it was. Corda is feared very much, but not as much as his two brothers, Pavor and Vincus.