electric eel 
noun
A large eel-like freshwater fish of South America, using pulses of electricity to kill prey, assist in navigation, and for defence.
- Electrophorus electricus, the only member of the family Electrophoridae.
- An added attraction will be the ‘Aqua Show’ from Chennai with sea lions and electric eels and exotic fish.
- Describing a canoe trip through the remote Napo River system in Ecuador, she notes that: Piranha fish live in the lakes, and electric eels.