A relative of the piranha, the Pacu is known as the Nutcracker, and you could probably guess why.
Somehow, the Pacu is making its way to Britain's water after already being sighted in the USA, Paris, and Denmark. A native species of the infamously terrifying Amazon River, the Pacu has a set of teeth that basically look like human teeth.
Better yet, that set of teeth is known for "chomping on human testicles" simply because they're known for chomping on nuts and acorns that fall into the waters. So how are they traveling so far from South America?
Well, they're sold as pets and many fear that the little suckers that have shown up outside the continent have been released into the wild by pranksters or negligent owners. Below is a video of a Pacu pet cracking a Brazilian nut open in a tank.
In addition, Pacu can live in captivity for at least 20 years and average around 15 years in the wild, so the threat is far from gone. A New Jersey father and son angler pair caught a Pacu for the first time in 2014, and the story went viral because of the images taken of the Pacu's scary human teeth.
The testicle-biting isn't a myth, either as the Pacu "bite because they're hungry, and testicles sit nicely in their mouth...fishermen in South America attacked by the pacu have reportedly bled to death after losing their testicles in the fish's vicious teeth."
If you happen to catch one of these fish or notice one very scary piranha-like creature roaming in the waters near you, called your DNR or Fish & Game Commission ASAP to report the sighting.