A 2015 American Direct-to-Video Action Horror directed by Christopher Ray that serves as a follow-up to 2-Headed Shark Attack.

A group of passengers fight to survive when their ship is attacked by a three-headed shark.

The film stars Danny Trejo, Karrueche Tran, Jason Van Dam, Anna Mercedes Morris, Bob Constance, and Preston Simmons.

It was released on July 20, 2015 by The Asylum. It was followed by 5-Headed Shark Attack in 2017.

Tropes for the film:

• From Dress to Dressing: Both Maggie and Allison use their shirts to bandage some of the injured passengers.
• Hero of Another Story: Mark, the Sole Survivor of the kids partying on the island in the opening scene, reappears in the last act with a harrowing tale of having spent days barely avoiding being eaten by the shark as it learned to crawl across land.
• More Expendable Than You: Maggie is preapred to swim out into the water to distract the shark and have it chase her as the others escape, but Dr. Thomas dives in first, refusing to let one of her team do that for her.
• Ms. Fanservice: Rosemarie, many of her fellow passengers, and most of Mark's female friends, and of the women at the environmentalist research station wear bikini tops throughout much if not all of their screen time, and Laura Thomas gets a nude scene while changing.
• Multiple Head Case: The different heads of the shark occasionally nudge irritably at one another, or try to snatch the same human victim away from one another like competitors.
• Spoiled Sweet: Rosemarie is implied to come an affluent and influential family, insists on paying for drinks after a bartender tells Rosemarie that her money is no good there, and is appropriately grateful and helpful to the rest of the group as they try to survive together, with some downplayed Team Mom moments.
• Tagline: "More heads, more deads!".
• What Happened to the Mouse?: The injured tour boat passengers Maggie, Alison and Rosemarie were bandaging are left behind as the shark comes back but since it doesn't end up sinking the ship they were on due to being distracted by an attack, their fate is unknown.