Finneon is a small fish Pokémon with a football-shaped body. The bottom half of its body is light-blue while the top half is black. A purple stripe runs across Finneon's horizontal length. Finneon has small blue pectoral fins, two black oval-shaped dorsal fins and purple eyes. Finneon's most notable feature is the pair of caudal fins that resemble a pair of blue butterfly wings with purple spots. Because of its wing-like fins, it is known as "The Beautifly of the Sea".
Finneon can use various Water-type attacks such as Water Gun and Surf as well as Ice Beam and Blizzard. To coincide with the fact that Finneon looks as if it has a pair of butterfly wings, it can learn Silver Wind, Gust and U-turn.
Finneon live in bodies of water such as creeks, rivers, lakes, seas, and oceans. The bottom lobes of a female's tail fin are bigger than a male's. It travel in schools, sometimes grouping with Lumineon.