Scarface

Scarface was a rather infamous killer shark who often attacked the borders of Atlantica. He was well-known enough that Aquata instantly recognized him. He was so-named for a large gash on his right eye. Because he was approaching the border of Atlantica, King Triton gave a warning to the citizens, and because of this, he had to postpone a concert until further notice. Because he was ultimately still a living creature, Triton wasn't willing to kill it unless it directly tries to attack Atlantica. Ultimately, Scarface managed to find Sebastian (who ironically expressed he didn't find Scarface with relief) when trying to find Ariel, forcing him and Flounder to flee and ended up cornered, although Flounder's unwanted girlfriend, Guinevere Coral "Jenny" Guppy, managed to yell at Scarface's face, buying the three enough time to hide in the cave. Ariel was then notified by Jenny (who escaped to warn her of Scarface attacking them, being small enough to fit through the only other exit), who then lured Scarface to a fishing ship owned by Prince Eric (who was himself hunting for Scarface). Scarface then ended up harpooned by Eric (who thought Ariel was a dolphin), ending his reign of terror.

Aquatic creatures were not his only victims, as Eric mentioned that his kingdom had to deal with Scarface's attacks as well, and that his own father had to fight him (it is also implied that his father was the reason for Scarface's scar).