* Giant eel: This is a straightforward, descriptive term.
* Moray eel: While not all morays are large, some species like the Giant Moray can reach impressive sizes.
* Conger eel: Conger eels are known for their large size, often exceeding 6 feet in length.
* Specific species name: The largest eels are often referred to by their scientific name, such as the "Giant Snake Eel" (*Ophichthus rex*) or the "Giant Moray" ( *Gymnothorax javanicus* ).
Ultimately, the term used will depend on the context and the specific species being discussed.