World's Biggest Stingray

E1

Thailand's giant stingrays and the whip rays of Australia can grow up to 16 feet and 1,300 lbs.

River Wolf

E2

Wolf fish, known locally as haimara, can reach a metre in length and is said to hunt humans.

Amazon Shocker

E3

There's a freshwater fish with a shock five times more powerful than a US wall socket.

Frankenfish

E4

The Thai snakehead is said to be able to move on land, and has apparently spread to US waters.

Silver Devil

E5

In Nicaragua, Zeb faces his most difficult battle hunting for one of the biggest monsters.

River Jaws

E6

Some shark species can survive in freshwater as well as salt.