Pacu, as this fish is incorrectly called in place of the violent spawn of hellfire that it is, happens to be a native of South American freshwaters. Pacu is a relative of the Piranha, but mostly it is an omnivore with vegetative tendencies and prefer nuts and fruits; except for when they attack and kill other fish, or chomp on human nuts.
The creepiest part about the fish has to be the uncanny resemblance its teeth have with human teeth. Take a look at the images, and you will see how closely they resemble human teeth. So here is Pacu, a fresh water fish with human teeth, and a taste for human testicles.