Leafeon is a quadruped mammal whose most distinguishing features are its lithe body structure and vegetation protruding from its body. Its tail and ears are stylized to resemble torn and tattered leaves. Besides the leaf-like ears and tail, there are a multitude of smaller leaves growing from its body; leaves grow out from the knee joint areas on the forelegs and hind legs, its chest and its back. A larger curled leaf grows from the middle of its forehead and is the same soft-green color of all the other leaves. It has the body structure which incorporates traits of a fox, but shares many cat like qualities, as well as plant-like characteristics.
Leafeon has appeared under the ownership of Zoey. It appeared alongside Zoey's Mismagius in a Grand Festival Semi Final contest battle with up against Nando's Kricketune and Lopunny. It is not known if Zoey's Leafeon evolved from an Eevee or not. Not much is known about this Pokémon.
According to the Diamond and Pearl Pokédex, Leafeon and Glaceon's footprints are the same (this may be related to the fact they both evolve under similar conditions, leveling up near a special rock).
Like Espeon, Leafeon has a type-disadvantage against its evolutionary counterpart (Umbreon and Glaceon respectively). The psychic-type Espeon is weak against the dark-type Umbreon and the grass-type Leafeon is weak against the Ice-type Glaceon. Interestingly both Espeon and Leafeon are associated with the sun and moves relating to it, as Espeon is the Sun Pokemon (and learns Morning Sun via leveling up and Sunny Day via TM) and Leafeon uses the sun for photosynthesis (and learn Sunny Day & Synthesis via leveling up and Solar Beam via TM).
Unlike Espeon, Leafeon does gain a type-advantage against one of the evolutions of Eevee, as the Water-type Vaporeon is weak against Leafeon's grass-type.
In addition to Glaceon, the Leafeon has a type disadvantage against the Fire-type Flareon. This makes Leafeon and Vaporeon (as Vaporeon's water-type is also weak against to the Jolteon's Electric-type) the only evolutions of Eevee weak against the types of 2 evolutions of Eevee while they are also strong against at least 1 evolution of Eevee (Leafeon is strong against Vaporeon, while Vaporeon is strong against Flareon (which is strong against Leafeon).
Both Leafeon and its counterpart Glaceon are weak against Flareon.
Like all Eeveelutions, Leafeon has traits of various mammalians, such as cats and foxes. Its cry sounds similar to a cat's meow. Leafeon's coloration is very similar to that of a siamese cat, with similar marking patters on its feet and tail. It also strongly resembles the red fox, citing its lithe body structure and brush like marking on its tail. The red fox lives in densely forested areas which may have served as the inspiration for Leafeon's affinity with plants and vegetation. Leafeon might also be inspired by feral cats.
Leafeon's name is a combination of the words "leaf" (due to its Grass-typing), and "eon" meaning an indefinitely long period of time.