Finneon is a small fishlike Pokémon with an ellipsoid body. The bottom half of its body is light-blue while the top half is black. A pink stripe runs across either side of Finneon's horizontal length. It has small blue pectoral fins, two black oval-shaped dorsal fins, and pink eyes. Finneon's most notable feature is the pair of caudal fins that resemble a pair of blue butterfly wings with pink spots. The bottom lobes of a female Finneon's tail fin are bigger than a male's. Finneon's pink stripes and spots can absorb sunlight, which allows those areas to shine vividly at night. Finneon shines itself as a form of camouflage, as well as to attract prey.
Because of its wing-like fins and beautiful appearance, Finneon is known as "The Beautifly of the Sea" and "finery fish". It lives in bodies of water, and it travels in schools, sometimes with Lumineon. Finneon is popular with divers; as a result, it is found living near resorts that feed them. It swims near the surface during the day to absorb sunlight, then dives into deeper waters at night. It is able to jump high and breach the water's surface with its tail fins, where it is then caught by its natural predator Wingull.
What a gorgeous sight this Pokémon is as it swims with its long, pink-painted caudal fins fluttering behind it. Finneon's beautiful appearance has led to its nickname: "finery fish."
If you see the pink patterns on Finneon’s tail fins shining at night, that means it stored up plenty of sunlight during the day. Isn’t Finneon beautiful when it flutters its fins like a pair of delicate wings?
Four Finneon appeared in Yo, Ho, Ho! Go, Popplio!, with one being wild and the other three appearing in a fantasy. Lana gave the wild one some food after capturing it by fishing. It was later captured by Team Rocket.
Finneon, the Wingfish Pokémon. Because of its twin-tail fins that flutter like wings when swimming, Finneon has been called "The Beautifly of the Sea."
Finneon's large tail fins are similar to the freshwater butterflyfish, and they also resemble wings of actual butterflies. It also resembles a neon tetra or a cardinal tetra. Its strong leaps from the water's surface is a known behaviour in flying fish — including how they are easily picked off by birds while airborne.
Name origin
Finneon may be a combination of fin and neon.
Keikouo may be a combination of 蛍光 keikō (fluorescence) and 魚 uo (fish).