Its skin is golden orange. It has green fins on its back and sharp teeth. He is also very long.
The Giant Golden Eel is the primary and true antagonist in "The Curse of the Hex." Madame Hagfish sends SpongeBob and Mr. Krabs to get the golden coin inside his throat. SpongeBob and Mr. Krabs then found the cave and went in there. When they found the eel sleeping inside, SpongeBob accidentally trips over into the water in the cave, making such loud noises that caused the eel to wake up. When the eel woke up, Mr. Krabs grabbed SpongeBob for protection. The eel hit SpongeBob with its large strong tail and had the sponge land far away as the eel grabbed Mr. Krabs with its tail and strangled him. Afterwards, SpongeBob lightly punched it, causing the eel to let go of Mr. Krabs. SpongeBob punched it again and the eel spit out the golden coin. After giving Madame Hagfish the coin, Mr. Krabs told SpongeBob that there is no such thing as curses or magical sea monsters right before the Giant Golden Eel came to the Krusty Krab, scaring all the customers away.
At the end of the episode when it bursts out of the Krusty Krab, it looks like a jack in the box.
The Giant Golden eel is most likely based on the giant moray eel, a large eel that lives in the Indo-pacific Ocean.
The Giant Golden eel is one of four eels (so far) in the series. Here are the others.