Piranha is a horror franchise that comprises five horror-comedy films. The original film is a parody of the 1975 film Jaws.
Two teenagers come upon an apparently abandoned military installation at night. They take advantage of what appears to be a swimming pool to Nude swimming. The teenagers are attacked by an unseen force in the pool and disappear under the water.
Off the coast of a Caribbean island, a young couple flee a hotel to have sex in the sea. But they swim into a sunken wreck which is also a piranha lair and they are both killed and eaten by the unseen piranha.
During the night, Barbara and her boyfriend David sneak into a closed-down army test site and discovered a pool. They go swimming but are attacked and killed by an unseen force in the pool. The next day, J.R. Randolph the uncle of Barbara, hires private investigator, Maggie McNamara, to investigate the incident, believing it to be a runaway.
After a sudden underwater tremor sets free scores of the prehistoric man-eating fish, an unlikely group of strangers must band together to stop themselves from becoming fish food for the area's new razor-toothed residents.
After the events at Lake Victoria, the pre-historic school of blood-thirsty piranhas make their way into a newly opened water park.