Piranhas

Piranhas are small predatory fish that have become a large part of popular culture due to their aggressive feeding behavior - which has been exaggerated in countless media to portray them as man-eating monsters.

Much like sharks, Piranhas in fiction are vicious, intelligent and extremely hungry - they also swarm their victims much as their real-world counterparts do: unlike the real-world Piranha however most fictional portrayals show them as actively hunting down humans.

The idea of piranhas as vicious man-eating monsters come from local myths that the fish can strip full-grown humans and cattle of meat in seconds and are exclusive carnivores (in reality they are omnivores) - however despite these myths being proven false there are accounts of piranhas occassionally seeking humans as prey, though much like sharks this is rarer than fiction depicts.

Piranhas appear as the main antagonists of at least four horror films of the same name which includes a prehistoric piranha and a mutated piranha also acts as a supervillain in Marvel comics.