An interesting portrayal of an Electric eel, with a whole gamut of colours and a very menacing looking face to compound it. To be honest, you might be better served by using the Morray Eel (Brightly coloured, tropical eel), or the Conger Eel, which can grow to 3m in length and be very nasty customers, with massive teeth and violent tendencies etc.
I like the way that you have portrayed the background, with a "Newgrounds aura" style, possibly in the hopes of making it into a level icon at some point. It works well, but I wouldn't recommend it for that purpose. Still, the use of bright colours against a menacing looking silhouette is very nice and workable, especially when the piece in question appears to have a series of lights running along it's sides.
I think that the additional thoughts of adding a length of fins is getting it a little away from the Eel family, but that's evolution for you, I suppose. As a result, poetic licence comes into play and gives a very pleasing effect to be used.
[Review Request Club]