Giant golden eel

The giant golden eel is a dangerous eel who appears as the main antagonist of the episode "The Curse of the Hex."

Description
It is a large golden-orange eel with pale green fins on its back and sharp teeth.

Role in episode
Madame Hagfish sends and  to get the golden coin inside its throat. SpongeBob and Mr. Krabs then finds the cave and goes inside. When they find the eel sleeping inside, SpongeBob accidentally trips over into the water in the cave, making such loud noises that causes the eel to wake up.

Afterwards, Mr. Krabs grabs SpongeBob for protection. The eel hits SpongeBob with its large, strong tail and knocks him far away. The eel then wraps Mr. Krabs in its tail and strangles him. Afterwards, SpongeBob lightly punches it, causing the eel to let go of Mr. Krabs. SpongeBob hits it again, which causes the eel to spit out the golden coin.

After giving Madame Hagfish the coin, Mr. Krabs tells SpongeBob that there is no such thing as curses or magical sea monsters right before the giant golden eel comes to the Krusty Krab, scaring all the customers away.

Trivia

 * At the end of the episode when it bursts out of the Krusty Krab, it looks like a jack-in-the-box.