Adegan eels were snake-like creatures indigenous to Ossus. The planet Ossus was located in the Adega system, hence the name.
They were also eaten by the royalty of Empress Teta. The leaders of the Krath used the eels in the takeover of the Empress Teta system.
When trying to buy spice from Nem'ro the Hutt during the Cold War, Nokril offered him Adegan eels. The spice dealer Getzo wished to buy Nem'ro's spice and hired an individual to destroy Nokril's eel tanks.
- The Complete Star Wars Encyclopedia