We have a brand new exclusive clip from the upcoming River Monsters episode, Amazon Assassins, which airs on Sunday, May 3 at 10 PM ET. Click below for our exclusive clip, which features some huge river fish.

In the darkest depths of the Amazon lurks a dinosaur. Legends tell of an evil spirit inhabiting an enormous fish. Taller than a man, it is covered in scales and crushes its prey with a tongue made of bone. Jeremy Wade encounters the legendary Arapaima.