Fire Shark

Fire Shark is a distinct species of Shark that swims the seas north of the Continental Bridge.
  Fires Sharks, as their name suggests, have a fiery bite and breath. While the waters of the sea quickly snuff out flames on the hull of a threatened ship, the true threat is the intense instant heat which exceeds 500 Degrees (Celsius). Temperatures of this range instantly char wood, indisintegrate polymers, and cause concussive expansions of steam which break hulls.
  These abilities coupled with their aggressive nature have resulted in the destruction of many ships that lack the proper protection.