Films: 2-Headed shark Attack (2012), Three-Headed Shark Attack (2015), Five-Headed Shark Attack (2017), Six-Headed Shark Attack (2017)
Height/Weight: Twice that of an average great white.
Summary: It only makes sense, doesn't it? The deadliest fish in the sea can only be deadlier if it's bigger, AND it has extra sets of teeth to eat people with. Alas, The Asylum gives us a fine example of milking such an idea dry even before "Sharknado" became a thing...
History: The first shark of such ferocity had two heads, and there was no explanation for why it was there. It just was. And it gave a lot of people Hell. The following multi-headed sharks would follow a similar route, except they'd be growing more heads to the point of absurdity.
Notable Kills: Anytime the shark scores a mutual kill with its heads. The more, the better.
Final Fate: The two-headed shark gets killed by a motor boat explosion, the three-headed one ends up chewing at itself during a feeding frenzy so much that it dies of blood loss, the five-headed one gets taken out by a bomb, and the six-headed one is killed by a more makeshift explosive. Also, it's heads start trying to eat each other soon afterward.
Powers/Abilities: The sharks can regrow their heads, and traverse on land for longer than most sharks.
Weakness: Heavy artillery. Also, they can only loose so much blood before expiring, and they will often eat their own heads.
Scariness Factor: 3-On a purely conceptual level, these sharks just keep getting scarier. The last two sharks in particular are like something out of a nightmare with just how unnatural they all look, especially the five-headed one's tail-mouth/fifth head. But unfortunately, all of them are bogged down by horrible CGI, and it just keeps getting worse with each film. Just let sleeping franchises lie, already!
Trivia: -It is not impossible for animals to inexplicably grow extra heads. It is known as polycephaly, and it mostly occurs in snakes and turtles. It is usually a result of there being conjoined twins.
-At one point, fisherman found dead two-headed shark pups, two of them belonging to a bull shark and a blue shark respectively. Some have speculated that it is a result of pollution from overfishing.