Also called pacu, it's a fish that shares a close resemblance to the piranha, having rather strong and terrifying looking teeth. The Pacu can grow to 55 pounds, has giant teeth and looks angry, but is usually the more friendly cousin of the piranha. It is generally found in rivers and streams in the Amazon and Orinoco river basins of lowland Amazonia. According to rumors, the pacu has a taste for biting men’s testicles.